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Greenlight
12-05-2016, 20:14
Have any three and four season backpackers or campers tried this hack on those chilly nights when you just can't seem to get warm enough to sleep?

1. Heat water with your stove, it doesn't have to be boiling.
2. Carefully put the water back into your Smartwater bottle or whatever you use (a small funnel helps) and replace the cap.
3. Stuff the warm/hot water bottle into a dry sock, and fold the top over on itself.
4. Snuggle and sleep.

If you're ground camping, this can be done without getting out of your sleeping bag, just like making breakfast inside your tent or vestibule.

Hammock hangers may have more logistical problems to solve, but it might be worth it if you're really chilled.

It's nothing but a modern method of what Scouts, trappers, and even Grandma Gatewood used to do by taking flat rocks warmed by the fire and putting them under the duff and moss they used for a sleeping pad.

egilbe
12-05-2016, 20:19
Several threads on here talking about doing this, pros and cons. I've never had any water bottles leak, but it is a slight risk. It does make one nice and toasty.

woodrow
12-05-2016, 21:54
This works great! Use a Nalgene stuffed in a wool sick for best results. I've used one near my feet and one on my chest during cold nights in the Whites while sleeping in a hammock. -36!

Elaikases
12-05-2016, 22:00
When hiking a little gear light in Virginia this spring with late snow flurries, I did this with my water before hiking and it worked great.

LIhikers
12-05-2016, 22:07
Not only does this keep you warm but it keeps your water from freezing too.

Leo L.
12-06-2016, 04:38
My wife did a guided hike in Mongolia once, and they had very rough weather, it was really difficult to keep warm while sleeping, even as she carried the best expedition-grade bag we own.
Their guides teached them to use the hot water bottle trick as you described.
But then they discovered the bodywork-trick (means, before heading to the bag do some 10-15 minutes of bodywork - no matter which kind of) and they loved this even more.
Several times the guide/cook did the cooking by means of hot stones in the stew, and after cooking handed the still very warm (cleaned-up) stones to the tourists. Worked better than the hot water bottle.
But be careful to not heat a stone over the stove - might explode.

peakbagger
12-06-2016, 06:37
Putting the water bottle in a ziplock bag is an easy backup if there is a leak.

Folks don't realize that heating a bottle of hot water weighs a lot less than bring extra gear to cover unusually cold conditions. In very cold winter camping conditions, I heat two bottles, one to be used right of way and the other I put in an insulated water bottle carrier (that I use for winter hiking), when the first bottle cools down, I take the other one out of the bottle carrier.

Greenlight
12-06-2016, 06:56
Yeah, the last thing you need at your camp site is exploding rocks. River rocks are the most likely culprits.


My wife did a guided hike in Mongolia once, and they had very rough weather, it was really difficult to keep warm while sleeping, even as she carried the best expedition-grade bag we own.
Their guides teached them to use the hot water bottle trick as you described.
But then they discovered the bodywork-trick (means, before heading to the bag do some 10-15 minutes of bodywork - no matter which kind of) and they loved this even more.
Several times the guide/cook did the cooking by means of hot stones in the stew, and after cooking handed the still very warm (cleaned-up) stones to the tourists. Worked better than the hot water bottle.
But be careful to not heat a stone over the stove - might explode.

colorado_rob
12-06-2016, 09:41
Putting the water bottle in a ziplock bag is an easy backup if there is a leak.

Folks don't realize that heating a bottle of hot water weighs a lot less than bring extra gear to cover unusually cold conditions. In very cold winter camping conditions, I heat two bottles, one to be used right of way and the other I put in an insulated water bottle carrier (that I use for winter hiking), when the first bottle cools down, I take the other one out of the bottle carrier.Yeah, HW bottles are an absolute staple for cold weather camping, used by zillions of folks in the mountaineering community, I just plain don't see any objection if simple care is used to make sure the cap is on right and tight. If you really are nervous about leaks, do the zip-lock thing. I've been using UL Gatorade bottles for this for 12-15 years, even on 3-week mountaineering expeditions where consequences of a leak are dire, zero problems.

On the AT, I saved weight for about 7-10 days when I swapped from my 20 degree bag to a 40 degree bag a bit early. I was just very careful about campsite selection and used a hot water bottle at night, and was fine in temps right around freezing. Really rough guess is that a HW bottle, sometimes 2, makes maybe a 10 degree difference in bag warmth.

One key point: you don't want to "blow your wad" with the heat wise right off, that's why slipping the bottle into a sock works so great; it moderates the heat output, making the bottle last most of the night with some warmth, vs. very toasty right off, but cold in a few hours.

saltysack
12-06-2016, 10:28
Yeah, HW bottles are an absolute staple for cold weather camping, used by zillions of folks in the mountaineering community, I just plain don't see any objection if simple care is used to make sure the cap is on right and tight. If you really are nervous about leaks, do the zip-lock thing. I've been using UL Gatorade bottles for this for 12-15 years, even on 3-week mountaineering expeditions where consequences of a leak are dire, zero problems.

On the AT, I saved weight for about 7-10 days when I swapped from my 20 degree bag to a 40 degree bag a bit early. I was just very careful about campsite selection and used a hot water bottle at night, and was fine in temps right around freezing. Really rough guess is that a HW bottle, sometimes 2, makes maybe a 10 degree difference in bag warmth.

One key point: you don't want to "blow your wad" with the heat wise right off, that's why slipping the bottle into a sock works so great; it moderates the heat output, making the bottle last most of the night with some warmth, vs. very toasty right off, but cold in a few hours.

Good to know you've never had problems with Gatorade bottles with hot water....assume it's not boiling water?


Sent from my iPhone using Tapatalk

colorado_rob
12-06-2016, 10:37
Good to know you've never had problems with Gatorade bottles with hot water....assume it's not boiling water?


Sent from my iPhone using TapatalkPure boiling water poured into a G-ade bottle will distort it, though I've found it still works just fine as a regular bottle this way, but it did make me nervous, and once the bottle was distorted, I no longer used it as a HW bottle. I now pour 4-6 ounces or so of cold water into the bottle first, then pour the hot water on top of that, and that process seems to keep the bottle from distorting.

Another option some folks in my circle use is one of those polyethylene Nalgene's, much lighter than a regular lexan Nalgene, 3.5 ounces vs. 6.5. But I thoroughly trust my 1.6 ounce G-ade bottles, having used them this way so long.

saltysack
12-06-2016, 10:49
Thx I'll give it a shot


Sent from my iPhone using Tapatalk

MuddyWaters
12-06-2016, 11:14
Double post

MuddyWaters
12-06-2016, 11:16
Wheres the hack?
People been putting hot water in bottles as long as have had bottles

rocketsocks
12-06-2016, 11:40
I use a nalgene, for its heavey duty superiority!

peakbagger
12-06-2016, 12:06
The clear plastic Nalgenes hold up to hot water a lot better than the milky white variety.

rocketsocks
12-06-2016, 12:22
The clear plastic Nalgenes hold up to hot water a lot better than the milky white variety.
Yup...that's the ticket!

egilbe
12-06-2016, 13:16
Hunersdorf water bottles.

importman77
12-06-2016, 13:29
I'd like to add one thing about placement. This may or may not be true but I learned somewhere that placing the water bottle between your legs, near your crotch area is the best way to benefit from this. Supposedly, by putting it there it's near your femoral artery and it heats the blood as it flows by there, and the blood flows throughout your body and makes you warmer. Like I said, I don't know how much difference it makes but that's where I've always placed it and it works for me.

swisscross
12-06-2016, 17:35
If temps, expected lows in the 20's or slightly lower (using my 30 degree bag) I carry a 16oz Nalgene. 1/2 the size of their common and about half the weight.
I too put between my legs at crotch area.
Never considered using a sock.
Use the water to make warm chocolate milk in the morning.

Secondmouse
12-07-2016, 04:24
I admit. the one time I tried this it didn't stay warm very long. how long does it stay warm and do you have to keep heating water up all night?..

importman77
12-07-2016, 06:48
I admit. the one time I tried this it didn't stay warm very long. how long does it stay warm and do you have to keep heating water up all night?..

Secondmouse, If you put it in a sock and keep in inside your sleeping bag it will stay warm for hours. Or at least that's my experience. I spent a very cold, windy night on the platform on the outside of Overmountain shelter and my Nalgene was still fairly warm when I awoke early the next morning.

peakbagger
12-07-2016, 07:32
If your sleeping bag is just plain inadequate, a water bottle is not going to solve the fundamental issue. I got caught in unusually cold conditions one year in VA, clear skies in a bivy in the open and estimated 15 degrees with a 30 degree bag. I ended up leaving the stove set up outside the bivy and having to heat up another bottle around 2 AM. I could have lugged a heavier 10 degree bag for the rest of the trip but that was the only night in five weeks I needed it.

MtDoraDave
12-07-2016, 07:48
Smart water bottles will shrink considerably when you put hot water in them, so be careful about how hot the water is.

I discovered this on a cold morning (coincidental) after slipping on ice 6 times in 2 days - one of the falls cracked my filter/pump. After letting the boiled water cool for a good 10 minutes, it turned my 1 liter smart water bottle into about .6 or .7 liters.

The only reason I put water bottles in my sleeping bag is to keep them from freezing. My sleeping bag is plenty warm enough. I suffered through one night a couple years ago, and vowed to buy a sufficient sleeping bag. I went with a 0 degree rated bag because I'd rather carry an extra pound than risk hypothermia.

In another thread, a couple people spoke of the inherent risk of putting water inside your sleeping bag. If the bag gets wet, the "hot water bottle hack" may kill you or at least make you miserably cold for a night or two....

cmoulder
12-07-2016, 09:04
.............The only reason I put water bottles in my sleeping bag is to keep them from freezing. My sleeping bag is plenty warm enough. I suffered through one night a couple years ago, and vowed to buy a sufficient sleeping bag. I went with a 0 degree rated bag because I'd rather carry an extra pound than risk hypothermia. .........

I agree strongly with this. The sleep system should be adequate for the temperature without dependence upon external heat in the event that heating up water for a hot water bottle is not practical or perhaps not possible.

rocketsocks
12-07-2016, 11:03
All a bag does is retard heat loss, using a hot water bottle just brings a little coziness to the party while you fall asleep.

colorado_rob
12-07-2016, 11:24
All a bag does is retard heat loss, using a hot water bottle just brings a little coziness to the party while you fall asleep.Yep, in fact my wife could probably not winter camp, an activity we love and do all the time, without her trusty HW bottle down near her feet. She uses a -10 degree bag in +10 weather and still gets cold feet at night w/o a bottle. BTW: she always uses a polyethylene Nalgene (the 3.5 ounce, 1-liter bottle), she has one dedicated to this purpose, it has never deformed with pure boiling water.


Smart water bottles will shrink considerably when you put hot water in them, so be careful about how hot the water is.

I discovered this on a cold morning (coincidental) after slipping on ice 6 times in 2 days - one of the falls cracked my filter/pump. After letting the boiled water cool for a good 10 minutes, it turned my 1 liter smart water bottle into about .6 or .7 liters.

In another thread, a couple people spoke of the inherent risk of putting water inside your sleeping bag. If the bag gets wet, the "hot water bottle hack" may kill you or at least make you miserably cold for a night or two....

Smart water bottles certainly do NOT work for this reason plus they are hard to fill up with their narrow mouths. G-ade bottle have a wide enough mouth that they are easier to fill, plus they seem to not shrink with hot water poured in. The bottom does deform, out in fact, but with a few ounces of cold water poured in first, this doesn't seem to happen.

I wonder if, in the history of the world, anyone has died from a HW bottle "leak"? I sincerely doubt it. First, why would they leak to begin with? The only credible failure is not placing the cap on correctly. Certainly this has happened, but it really only take a slight amount of care to make sure the cap is secure. It's not rocket science. What other mechanism for failure is there? Do you sleep with sharp objects, like knives? Maybe some do....

This is such a tried and true and common practice, especially in the mountaineering community.

Starchild
12-07-2016, 14:49
Wheres the hack?
People been putting hot water in bottles as long as have had bottles


I was going to post the same thing, actually I composed such a question, but refrained from posting and deleting it. I figured it might hurt the OP's feelings and more accepting of the broadened definition of the word hack.

A hack is a useful misuse of a product or some unintended useful modification. But as you said hot water in a bottle is almost as old as the bottle itself. I did justify it as it may be a hack of the use of a sock, though that is old hat in backpacking also.

So yeah, no hack, just spreading the word of how to stay warm on a cold night.

Secondmouse
12-08-2016, 18:02
Secondmouse, If you put it in a sock and keep in inside your sleeping bag it will stay warm for hours. Or at least that's my experience. I spent a very cold, windy night on the platform on the outside of Overmountain shelter and my Nalgene was still fairly warm when I awoke early the next morning.

hahhaha I could have used that when I set up my hammock behind the Overmountain shelter. day was nice but getting cool, I fell asleep before dark but woke up shivering with a cloud whistling through my tarp. not fun..

cmoulder
12-08-2016, 19:05
I was going to post the same thing, actually I composed such a question, but refrained from posting and deleting it. I figured it might hurt the OP's feelings and more accepting of the broadened definition of the word hack.

A hack is a useful misuse of a product or some unintended useful modification. But as you said hot water in a bottle is almost as old as the bottle itself. I did justify it as it may be a hack of the use of a sock, though that is old hat in backpacking also.

So yeah, no hack, just spreading the word of how to stay warm on a cold night.

New word: Paleohack... been around a while. ;)

Whack-a-mole
12-16-2016, 00:54
One thing to watch out for, with this very old and common cold weather trick, is not to use cheap bottles that look like Nalgene bottles from discount retailers, the plastic will melt, and could cause a leakage problem. I don't use Nalgene bottles because of their weight, but if I'm going out when it's really cold, I'll go ahead and use one just to have it for this reason.

Engine
12-16-2016, 06:38
For nights when it's below freezing, a good multipurpose solution is to drop your water filter into the bottom of an extra large wool sock and then drop a filled hot water bottle in on top of that. I like a 16-ounce water bottle because I toss and turn a lot and it's easier to move around with a smaller bottle. It still stays warm for a long time, even with only 1/2 quart of water.

ScareBear
12-16-2016, 08:35
"I wonder if, in the history of the world, anyone has died from a HW bottle "leak"? I sincerely doubt it. First, why would they leak to begin with? "

Because a 200 lb sleeping adult rolled over on said water bottle whilst asleep, causing either the bottle to split or the cap to pop off. Either way, in a down bag, you are going to be sorry. Just sayin...

The need for a water bottle in your sleeping bag is because poor planning was involved, IMHO.

An easier solution is simply to put on your rain gear for a sort of VBL in your bag...or plan correctly and bring the proper sleep system...

Engine
12-16-2016, 10:12
...The need for a water bottle in your sleeping bag is because poor planning was involved, IMHO.

An easier solution is simply to put on your rain gear for a sort of VBL in your bag...or plan correctly and bring the proper sleep system...


The bottle is there exactly because of proper planning...

For a thru-hiker who is using a single bag or quilt to cover the entire distance, the HWB provides that extra bit needed during those few nights when the other components of the sleep system are just not quite enough. The added bottle has other uses in addition to those times when it is used as part of the hikers own personalized "Proper sleep system".

YMMV...

Greenlight
12-16-2016, 11:53
Starchild,

You're not gonna hurt my feelings, I have thick skin and appreciate the feedback. I didn't spend much time contemplating whether my use of the word hack was narrow or broad, I posted it because we're going into winter and it might help a newbie. I'm a relative newbie. :)


I was going to post the same thing, actually I composed such a question, but refrained from posting and deleting it. I figured it might hurt the OP's feelings and more accepting of the broadened definition of the word hack.

A hack is a useful misuse of a product or some unintended useful modification. But as you said hot water in a bottle is almost as old as the bottle itself. I did justify it as it may be a hack of the use of a sock, though that is old hat in backpacking also.

So yeah, no hack, just spreading the word of how to stay warm on a cold night.

garlic08
12-16-2016, 12:41
I use a variation of the HW trick on day trips in frigid weather. I always pack a down vest as a back-up, always pack a lunch, and always pack water. So I heat up the water at home, wrap it up in the down vest with lunch, then at lunch time I have warm lunch, warm water, and a warm down vest if needed. Once I handed around hot appetizers on a 13,300' summit on New Years Day to go with the champagne. Another time a partner had a crisis with freezing fingers in the morning, enough to want to turn around, but holding the bottle inside her jacket for a few minutes kept her on the trail.

Hot water in the sleeping bag is a no-brainer, as far as I'm concerned. It adds comfort to marginal situations. I know one guy on a mountaineering party who had his bottle leak from failure to close it correctly (some combination of ice crystals and mittens, he said), but he survived and finished the trip. I think that was before ziplocks were invented or something.

ScareBear
12-16-2016, 15:23
The bottle is there exactly because of proper planning...

For a thru-hiker who is using a single bag or quilt to cover the entire distance, the HWB provides that extra bit needed during those few nights when the other components of the sleep system are just not quite enough. The added bottle has other uses in addition to those times when it is used as part of the hikers own personalized "Proper sleep system".

YMMV...

I stand by my reply. The water bottle trick won't save your life and it will only provide warmth until the temperature inside the water bottle equals your body temperature, which won't be that long. If you must use the water bottle trick as SOP for a thru hike, then you are ill prepared. And, how in the world will the same bag/quilt, and a water bottle, get you from 20 degrees in March in GA to 90 Degrees in June? And everything in between? How does that work, again?
That bottle won't magically transform your 30 degree bag into a 20 degree bag. No bag is that versatile. No bottle is that big. However, a proper sleep system is that versatile. No water bottle is going to make that difference. A proper sleep system will. Sorry. YMMV.

Engine
12-16-2016, 15:38
I stand by my reply. The water bottle trick won't save your life and it will only provide warmth until the temperature inside the water bottle equals your body temperature, which won't be that long. If you must use the water bottle trick as SOP for a thru hike, then you are ill prepared. And, how in the world will the same bag/quilt, and a water bottle, get you from 20 degrees in March in GA to 90 Degrees in June? And everything in between? How does that work, again?
That bottle won't magically transform your 30 degree bag into a 20 degree bag. No bag is that versatile. No bottle is that big. However, a proper sleep system is that versatile. No water bottle is going to make that difference. A proper sleep system will. Sorry. YMMV.

You are missing the part about a "sleep system" of which the bottle simply exists to provide that extra bit of warmth on nights when the other components of the system are just falling short a bit. With a 20* EE quilt and a STS Thermoreactor liner I am quite comfy at 20* in lightweight longjohns. If I add my down puffy, fleece hat, and heavy wool Sealskinz socks I'm still sleeping at 10-12*. In the event it's going to be colder than that, I heat up water before bed.

Now, how many nights would you say it gets below 10* on the AT during thru hiker season? But, by your reasoning, I should be carrying a 0-5* bag that will just be too much most of the time, while my 20* quilt is flexible enough to allow sleeping just fine in summer temps. By the way, I could be naked on my pad in a breezy shelter and still not sleep in 90* weather, so that end of the argument is effectively mute.

ScareBear
12-16-2016, 15:59
You are missing the part about a "sleep system" of which the bottle simply exists to provide that extra bit of warmth on nights when the other components of the system are just falling short a bit. With a 20* EE quilt and a STS Thermoreactor liner I am quite comfy at 20* in lightweight longjohns. If I add my down puffy, fleece hat, and heavy wool Sealskinz socks I'm still sleeping at 10-12*. In the event it's going to be colder than that, I heat up water before bed.

Now, how many nights would you say it gets below 10* on the AT during thru hiker season? But, by your reasoning, I should be carrying a 0-5* bag that will just be too much most of the time, while my 20* quilt is flexible enough to allow sleeping just fine in summer temps. By the way, I could be naked on my pad in a breezy shelter and still not sleep in 90* weather, so that end of the argument is effectively mute.

You are getting close to what I am talking about when I say "PROPER SLEEP SYSTEM". It is a system whereby you utilize your bag, your clothing, your rain gear, possibly a space blanket if things go way South, and a liner or liner/bivvy. A 30 degree bag(for a man EN Comfort Rating of 30F) is more than sufficient to get the job done all the way to Maine. Without a water bottle trick. Quick example=My #3 Montbell SSS(30degree), my Klymit Insulated Static V Lite mattress, my ScottishSilkworm blend liner, my SOL Escape Bivvy, my Thorlo super-thick syn socks, my Mountain Gear/Marmot rain jacket/pants, ultralight Terramar tights and a fleece multi-pupose balaclava comprise my sleep system. Its good for 15 degrees to 90 degrees and other than the liner and bivvy are comprised entirely of gear that is in my pack on an AT distance hike no matter what. And, no water bottle. Even though I could use one of my 3 Litre Camelback canteens...I wouldn't sleep well with 3 Litres of water sloshing around inside my down bag. YMMV...everyone is different...

nsherry61
12-16-2016, 16:31
I stand by my reply. The water bottle trick won't save your life and it will only provide warmth until the temperature inside the water bottle equals your body temperature, which won't be that long. If you must use the water bottle trick as SOP for a thru hike, then you are ill prepared. . .
ScareBear, how much time have you actually spent sleeping in the back country in the winter?

There is nothing wrong with choosing, for yourself, to not use one or another techniques because you are not comfortable with them or because for whatever reason you don't want to. But, espousing knowledge about a widely used and very successful technique, when clearly you haven't spent time experimenting with it is not particularly helpful to yourself or your readers.

To directly address some of your comments:
1) Actually, the water bottle trick might save someones life since even a tiny bit of warmth might extend the life of a hypothermic person the few minutes needed to get help and keep them alive. But no, probably not in most cases. But then, if you have the ability to heat water for the water bottle, you can probably heat water to drink, so the whole issue of being life savings is not really the point anyway is it? It's about sleeping well and comfortably, for which a hot water bottle can be very helpful for many people.

2) How long will 1 L of water stay warm (by your definition, above 98.6*F)? Inside a sock or another insulated covering keeping a bottle warm for 3-6 hours pretty easy to achieve, so, pretty much all night long if you rig it appropriately.

3) How the heck is me planning to use a method that works well for me being "ill prepared"? If you can open your mind beyond your myopic arrogance, there are all kinds of great ideas and practices to be discovered even if you choose not to use some of them that works well for someone else.

For everyone else out there . . .
1) A leaky hot water bottle will make the bottom your your bag wet, not so much the top, and since the bottom of your sleeping system is insulated primarily from your pad, getting your bag wet on the bottom, although very unpleasant, it unlikely to be a complete disaster.
2) A hot water bottle can help with better sleep and rest when you are pushing your sleeping system. Some people sleep better with a second pillow. Some people sleep better with a hot water bottle at their feet. Most of us sleep better when we are at the right temperature, and a water bottle is one of many effective tools to achieve that goal.
3) Finally, if your sleeping bag is a bit damp, especially near the foot end where bags seem to often get damp, the heat of a hot water bottle does wonders in drying out your insulation where your feet don't produce enough heat to do it on their own. On more than one occasion I've had a slightly damp bag in cold conditions, where my feet were not warm without a water bottle, but, by morning, when the water bottle was no longer providing heat, my bag worked enough better that my feet were completely happy.

Engine
12-16-2016, 17:57
ScareBear, how much time have you actually spent sleeping in the back country in the winter?

There is nothing wrong with choosing, for yourself, to not use one or another techniques because you are not comfortable with them or because for whatever reason you don't want to. But, espousing knowledge about a widely used and very successful technique, when clearly you haven't spent time experimenting with it is not particularly helpful to yourself or your readers.

To directly address some of your comments:
1) Actually, the water bottle trick might save someones life since even a tiny bit of warmth might extend the life of a hypothermic person the few minutes needed to get help and keep them alive. But no, probably not in most cases. But then, if you have the ability to heat water for the water bottle, you can probably heat water to drink, so the whole issue of being life savings is not really the point anyway is it? It's about sleeping well and comfortably, for which a hot water bottle can be very helpful for many people.

2) How long will 1 L of water stay warm (by your definition, above 98.6*F)? Inside a sock or another insulated covering keeping a bottle warm for 3-6 hours pretty easy to achieve, so, pretty much all night long if you rig it appropriately.

3) How the heck is me planning to use a method that works well for me being "ill prepared"? If you can open your mind beyond your myopic arrogance, there are all kinds of great ideas and practices to be discovered even if you choose not to use some of them that works well for someone else.

For everyone else out there . . .
1) A leaky hot water bottle will make the bottom your your bag wet, not so much the top, and since the bottom of your sleeping system is insulated primarily from your pad, getting your bag wet on the bottom, although very unpleasant, it unlikely to be a complete disaster.
2) A hot water bottle can help with better sleep and rest when you are pushing your sleeping system. Some people sleep better with a second pillow. Some people sleep better with a hot water bottle at their feet. Most of us sleep better when we are at the right temperature, and a water bottle is one of many effective tools to achieve that goal.
3) Finally, if your sleeping bag is a bit damp, especially near the foot end where bags seem to often get damp, the heat of a hot water bottle does wonders in drying out your insulation where your feet don't produce enough heat to do it on their own. On more than one occasion I've had a slightly damp bag in cold conditions, where my feet were not warm without a water bottle, but, by morning, when the water bottle was no longer providing heat, my bag worked enough better that my feet were completely happy.

You successfully said what I was trying to say...

ScareBear
12-16-2016, 19:56
ScareBear, how much time have you actually spent sleeping in the back country in the winter?

There is nothing wrong with choosing, for yourself, to not use one or another techniques because you are not comfortable with them or because for whatever reason you don't want to. But, espousing knowledge about a widely used and very successful technique, when clearly you haven't spent time experimenting with it is not particularly helpful to yourself or your readers.

To directly address some of your comments:
1) Actually, the water bottle trick might save someones life since even a tiny bit of warmth might extend the life of a hypothermic person the few minutes needed to get help and keep them alive. But no, probably not in most cases. But then, if you have the ability to heat water for the water bottle, you can probably heat water to drink, so the whole issue of being life savings is not really the point anyway is it? It's about sleeping well and comfortably, for which a hot water bottle can be very helpful for many people.

2) How long will 1 L of water stay warm (by your definition, above 98.6*F)? Inside a sock or another insulated covering keeping a bottle warm for 3-6 hours pretty easy to achieve, so, pretty much all night long if you rig it appropriately.

3) How the heck is me planning to use a method that works well for me being "ill prepared"? If you can open your mind beyond your myopic arrogance, there are all kinds of great ideas and practices to be discovered even if you choose not to use some of them that works well for someone else.

For everyone else out there . . .
1) A leaky hot water bottle will make the bottom your your bag wet, not so much the top, and since the bottom of your sleeping system is insulated primarily from your pad, getting your bag wet on the bottom, although very unpleasant, it unlikely to be a complete disaster.
2) A hot water bottle can help with better sleep and rest when you are pushing your sleeping system. Some people sleep better with a second pillow. Some people sleep better with a hot water bottle at their feet. Most of us sleep better when we are at the right temperature, and a water bottle is one of many effective tools to achieve that goal.
3) Finally, if your sleeping bag is a bit damp, especially near the foot end where bags seem to often get damp, the heat of a hot water bottle does wonders in drying out your insulation where your feet don't produce enough heat to do it on their own. On more than one occasion I've had a slightly damp bag in cold conditions, where my feet were not warm without a water bottle, but, by morning, when the water bottle was no longer providing heat, my bag worked enough better that my feet were completely happy.

If you are counting nights spent at or below zero...at least 73 that I can remember without resorting to my journals. 60 of which were on snow. Below freezing? More than 200 something...why? Does that help/hurt my cred? Do I need to list nights spent above 9000 feet? How about blizzards? It is irrelevant. Because, instead of anecdotes, we can use science!

Remember thermal dynamics are your friend/enemy. In this case, its your enemy because it destroys your false theory that a one Litre water bottle that maintains temps above 100F for 6 hours can be of some aid to warming you. It can't, physically speaking. In order to transfer heat to you, to warm you, the fluid transferring the heat must lose its heat, in at LEAST direct proportion to the heat transferred. Rule #1 of conservation of energy. If your water bottle is so freaking insulated that it will maintain temps above 100F for 6 hours, it won't warm you at all!!! There won't be any energy(heat) transfer! OMG....I was going to say it isn't rocket science...but...look...you can't put a water temp greater than 140F in the water bottle or you will cause a third degree burn in SIX SECONDS. 130F? THIRTY SECONDS TO THIRD DEGREE BURNS. 120F? FIVE MINUTES TO THIRD DEGREE BURNS! You've seen an egg cooking on a sidewalk, right? http://www.accuratebuilding.com/services/legal/charts/hot_water_burn_scalding_graph.html

So, once and for all, let's put this water bottle placebo nonsense to bed, so to speak...your water can't be any hotter than 120F to start and it can't warm you below 99F. Below 98.6F, the water bottle will act as a heat sink and draw heat(energy) AWAY from your body and INTO the water bottle until the two substance temps(your body and the water) are equal. Then, YOUR BODY will assume the duty of maintaining the water's temperature at....gee...98.6 degrees...damn physics....Again, thermal dynamics at work. Now, I understand that the figures I quoted were for immersion in the water, however, from real life cases involving heat packs to the inner thighs of children who have fallen through ice or otherwise become acutely hypothermic, the incidence of severe third-degree burns is more likely described as a prevalence. I've done the research. I've seen the results, first hand. Do you have any idea how horrific a 2 inch by 2 inch third degree burn on the inside of your thigh is? Life-alteringly horrific.

In other words, a one Litre Nalgene will shed heat from 115F to 98F( a mean change of a mere 17 degrees!) far far far far more rapidly than 6 hours when in contact with a 98.6 degree object. Especially when the bottle is in direct contact with a cooler temp source, since physics demands the water in the bottle shed its energy to warm the cooler body that it is touching...
I would say YMMV, but...it's science....

ScareBear
12-16-2016, 22:50
And, just for reference, "myopic arrogance" would refer to the "Earth is flat" group, who must ignore science to validate their belief. Not the group that thinks "Earth is round" because of any number of easily proven measures(thanks Copernicus!). Kinda the same way some people steadfastly believe that a 1 Litre Nalgene bottle filled with 115 degree water will do much to warm you inside your sleeping bag, for any significant length of time and won't ever act as a heat sink to drain your body of heat(energy)....just sayin...

Engine
12-17-2016, 06:18
And, just for reference, "myopic arrogance" would refer to the "Earth is flat" group, who must ignore science to validate their belief. Not the group that thinks "Earth is round" because of any number of easily proven measures(thanks Copernicus!). Kinda the same way some people steadfastly believe that a 1 Litre Nalgene bottle filled with 115 degree water will do much to warm you inside your sleeping bag, for any significant length of time and won't ever act as a heat sink to drain your body of heat(energy)....just sayin...

All those professional mountaineers who have used this method for many years MUST be wrong...:-?

importman77
12-17-2016, 07:03
If you are counting nights spent at or below zero...at least 73 that I can remember without resorting to my journals. 60 of which were on snow. Below freezing? More than 200 something...why? Does that help/hurt my cred? Do I need to list nights spent above 9000 feet? How about blizzards? It is irrelevant. Because, instead of anecdotes, we can use science!

Remember thermal dynamics are your friend/enemy. In this case, its your enemy because it destroys your false theory that a one Litre water bottle that maintains temps above 100F for 6 hours can be of some aid to warming you. It can't, physically speaking. In order to transfer heat to you, to warm you, the fluid transferring the heat must lose its heat, in at LEAST direct proportion to the heat transferred. Rule #1 of conservation of energy. If your water bottle is so freaking insulated that it will maintain temps above 100F for 6 hours, it won't warm you at all!!! There won't be any energy(heat) transfer! OMG....I was going to say it isn't rocket science...but...look...you can't put a water temp greater than 140F in the water bottle or you will cause a third degree burn in SIX SECONDS. 130F? THIRTY SECONDS TO THIRD DEGREE BURNS. 120F? FIVE MINUTES TO THIRD DEGREE BURNS! You've seen an egg cooking on a sidewalk, right? http://www.accuratebuilding.com/services/legal/charts/hot_water_burn_scalding_graph.html

So, once and for all, let's put this water bottle placebo nonsense to bed, so to speak...your water can't be any hotter than 120F to start and it can't warm you below 99F. Below 98.6F, the water bottle will act as a heat sink and draw heat(energy) AWAY from your body and INTO the water bottle until the two substance temps(your body and the water) are equal. Then, YOUR BODY will assume the duty of maintaining the water's temperature at....gee...98.6 degrees...damn physics....Again, thermal dynamics at work. Now, I understand that the figures I quoted were for immersion in the water, however, from real life cases involving heat packs to the inner thighs of children who have fallen through ice or otherwise become acutely hypothermic, the incidence of severe third-degree burns is more likely described as a prevalence. I've done the research. I've seen the results, first hand. Do you have any idea how horrific a 2 inch by 2 inch third degree burn on the inside of your thigh is? Life-alteringly horrific.

In other words, a one Litre Nalgene will shed heat from 115F to 98F( a mean change of a mere 17 degrees!) far far far far more rapidly than 6 hours when in contact with a 98.6 degree object. Especially when the bottle is in direct contact with a cooler temp source, since physics demands the water in the bottle shed its energy to warm the cooler body that it is touching...
I would say YMMV, but...it's science....

I'm certainly not qualified to argue your points re science but I know that when I put the water in my Nalgene it's at approximately 212* depending on whatever elevation I'm at at the time, (boiling point of water ~212* F at sea level). I know that because I don't put it into the bottle until I've watched it boil. I assume the sock I put on it is what has saved me from those third degree burns you mentioned. So your assertion that we're only working with a drop from 115* to 98.6* is false. Also, the insulation of the sock allows for a slow but steady transfer of the heat from the bottle to your body. Thus it maintains temperatures above 98.6 for most of the night. I would also argue that putting the bottle into your bag a little while before you plan to climb in to sleep helps to warm the bag and will keep you from getting chilled when you get into it. Again, I'm no science geek but I believe it's a lot easier to stay warm inside of your bag than it is to get warm after you've gotten chilled from climbing into a cold bag.

Engine
12-17-2016, 08:15
From the Everest Base Camp trip packing list on YExplore.com

" Hard plastic water bottles that can hold hot liquids
Will be used for hydration while in sub-freezing temperatures in the morning.
Will also be used as hot water bottles to be placed in your sleeping bag at night."

From Whittaker guide tips for sleeping warm

"A hot water bottle is key!"


From Andrew Skurka "Tips for quality sleep in the Backcountry"

"...For example, putting a hot water bottle in your sleeping bag works really well..."

There are literally thousands of examples resulting from a Google search, so I guess it's correct to state it really isn't rocket science...

ScareBear
12-17-2016, 08:39
The more you insulate the Nalgene, the slower the rate of transfer of heat will become. It is the transfer of heat to either the air in the bag and/or your body itself that warms you. By insulating, you are conserving the energy in the bottle. The more you conserve energy in order to slow the rate of energy loss(transfer) to the air and/or your body, the less warmth you get out of the bottle that will have any actual effect on warming you or increasing your body temperature. In other words, the longer the energy stays in the bottle, the lower the energy output of the bottle will be. Physics 101. So, first the thread just talked about water bottles as the hack. I didn't point out that 120F is about the upper safe limit of that bottle's temperature. Then somebody brought up the sock hack for the hack. That's fine, but everyone forgot about science and insulation and energy transfer. A perfect example of insulation and energy transfer. Put a frozen anything into a closed cell foam can coolie. Let it sit as long as you want. Touch the outside of the coolie. Get it? The more you insulate the less energy can be transferred. The less you insulate, the larger the amount of energy transfer can be achieved and the speed of the loss of heat from the superior object will increase...does a sock magically hit the theoretical sweet spot between energy transfer from the superior object to the inferior object and energy conservation of the superior object for maximum efficiency in transferring energy to the inferior object? That would, indeed, be magical. Or at least the world's greatest coincidence....

Now, about boiling water in a Nalgene? The clear bottles(polycarbonate) are fine for boiling water. The softer white bottles are not. Those are polyethylene and that material begins to lose tensile strength before 212F and I believe begins to lose its solid form around 230F or so. I'd never put boiling water into one of these...YMMV...

To me, the potential risks of the hack, especially at 212F, outweigh the potential gains, which to me would be either quite short in duration or quite low in effect. You can't have high effect/high duration with a non-replenishing finite energy source. Remember, we are talking about sub-freezing and/or sub-zero temperatures that would require this hack, everyone seems to be forgetting about the energy loss from the bag as part of the equation as to the rate and duration of energy loss from the water bottle as well.....

ScareBear
12-17-2016, 08:46
I don't dispute that the bottle trick will warm you. I dispute both the amount of warming and the duration of warming from the anecdotal accounts. Especially the 6 hours of lasting energy in a 1 Litre Nalgene bottle that would have any effect on your body temperature...science doesn't work that way...it is only 1 Litre! It is only H2O!!!

Engine
12-17-2016, 09:04
According to Reference.com/science the average human generates around 315 BTUs while sleeping. If we consider the BTUs stored in 1 liter of water, only counting the energy released as it cools from 210* (some heat lost in transfer to bottle) to 99* (still warmer than normal human core temp), there are approximately 249 BTUs of energy available for release. Given that the bottle in a sock method slows the release of energy and the commonly accepted number until the bottle cools is between 4 and 6 hours, we'll use 5 hours as the time for total additive energy release.

That equates to 49.8 BTUs an hour of additional energy provided inside the sleeping bag. This works out to a 15.8% increase in heat produced inside the bag for those 5 hours. That's a considerable difference which could turn a horrible night into a tolerable or even decent night of rest.

Engine
12-17-2016, 09:05
I don't dispute that the bottle trick will warm you. I dispute both the amount of warming and the duration of warming from the anecdotal accounts. Especially the 6 hours of lasting energy in a 1 Litre Nalgene bottle that would have any effect on your body temperature...science doesn't work that way...it is only 1 Litre! It is only H2O!!!

Is your hot water heater in your house insulated? Why might that be?

ScareBear
12-17-2016, 09:10
And, finally, there is this thing called "perception" and this thing called "reality". Let me give you a perfect example of both and you may begin to see my point more clearly.

Anything warmer than the air inside or surface temperature inside your sleeping bag is going to seem warm to you. Even if that thing is below 98.6F. That is perception.

Anything warmer than the air or surface temperature inside your sleeping bag that is below 98.6 degrees will absorb energy from your body in order to reach temperature equality and does the opposite of warming you. To the extent that your body can't keep up with it's own energy loss, you get cold. That is reality.

ScareBear
12-17-2016, 09:13
Is your hot water heater in your house insulated? Why might that be?

My hot water heater isn't heating my house. Or even the utility room. It is insulated to prevent just that occurrence. Otherwise, you wouldn't have hot water in your shower...I don't think YMMV...

ScareBear
12-17-2016, 09:15
According to Reference.com/science the average human generates around 315 BTUs while sleeping. If we consider the BTUs stored in 1 liter of water, only counting the energy released as it cools from 210* (some heat lost in transfer to bottle) to 99* (still warmer than normal human core temp), there are approximately 249 BTUs of energy available for release. Given that the bottle in a sock method slows the release of energy and the commonly accepted number until the bottle cools is between 4 and 6 hours, we'll use 5 hours as the time for total additive energy release.

That equates to 49.8 BTUs an hour of additional energy provided inside the sleeping bag. This works out to a 15.8% increase in heat produced inside the bag for those 5 hours. That's a considerable difference which could turn a horrible night into a tolerable or even decent night of rest.
In a vacuum, your theory is valid. You forgot a huge variable in your equation. What is the rate of energy loss from the bag to the atmosphere in the tent? Hmmmm???? If there was no energy loss from the bag to the atmosphere, you wouldn't have needed the bottle in the first place....doh....
In a vac

ScareBear
12-17-2016, 09:21
The reason you "need" the bottle trick is because(somehow) your bag's temp rating and the air temp are not close. The bigger the difference between your bag temp rating and the air temp, the more you "need" the bottle trick. And, as that gulf between bag temp rating and air temp widens, you will see the linear increase in the loss of energy from the bottle rise proportionately. Again, Physics....

Engine
12-17-2016, 09:27
In a vacuum, your theory is valid. You forgot a huge variable in your equation. What is the rate of energy loss from the bag to the atmosphere in the tent? Hmmmm???? If there was no energy loss from the bag to the atmosphere, you wouldn't have needed the bottle in the first place....doh....
In a vac

That argument has no bearing at all on what I stated. I discussed energy release from available heat sources. The loss of energy from the bag is a constant, so in a given bag, the stated increase in available heat will still provide 15.8% more energy.

You are now on a tangent since your original argument is losing steam (pun intended...:D)

Engine
12-17-2016, 09:29
My hot water heater isn't heating my house. Or even the utility room. It is insulated to prevent just that occurrence. Otherwise, you wouldn't have hot water in your shower...I don't think YMMV...

Go feel the outside of your water heater and then tell me it isn't providing some heat for the room it's in...no such thing as 100% efficient insulation. The sock works the same way, it SLOWS the release of energy.

I done trying to explain something that so many experienced backcountry guides and adventurers have known for so long...

ScareBear
12-17-2016, 09:41
Any idea how many BTU your water heater puts out? Jeeeeeeeeezus....

The loss of energy from the bag may be constant(it isn't!) but you omitted it from your equation. The temperature in the bag is going to equalize at around the temperature rating of the bag, based on your body's thermal output. To the extent that your bag's temp rating is ABOVE the ambient temperature, the bag will lose heat on the inside to the ambient air temperature on the outside. That is a doh and a give, right? You aren't calculating what that rate of temperature loss is and the rate varies by the ambient temperature, since the output of your engine is fairly constant....again...its only science...

I am done trying to explain physics and thermal dynamics to somebody who will never understand it. That's ok. Everyone is different. I still think you are an OK guy with lot's of valuable information to give people regarding wilderness backpacking. However, I never said the bottle trick doesn't "work", just that it doesn't "work" in the manner some of the anecdotal evidence seems to suggest. At least it "can't" work in the manner some of the anecdotal evidence seems to suggest because....well....SCIENCE...just sayin...

garlic08
12-17-2016, 10:03
Looking at the numbers another way: One Calorie is the amount of heat needed to raise one kilogram (one liter) of water one degree C. Best case scenario at sea level, in a one liter container insulated well enough to prevent contact burns, the most heat that can transfer will be 100C - 37C (average body temp) or 63C. That's 63 Calories in the transfer. Compare that to the 215 Calories in a Snickers bar. Are my number wrong? Using them, you're much better off eating something before getting in the bag. (That's assuming you have a healthy metabolism and are able to eat.)

I use the same argument to support my stoveless camping style. A hot drink contains very little useful heat energy, considering you really can't swallow anything in volume much hotter than 120F. But you can't discount the comfort factor, especially if a loved one supplies the hot drink. And for a person with borderline hypothermia, it can help more quickly than food.

But a hot bottle in the sleeping bag sure feels good. And since you want to protect that water from freezing anyway, go ahead and heat it up first, as long as you have the fuel.

peakbagger
12-17-2016, 10:11
The problem with advocating an "adequate sleep system" is that it inevitably will be far more than needed by thru hiker 99% of the time. Equipment selection by a thru hiker is necessarily a trade off of weight versus comfort/survival. With the exception of survival situation where the individual is losing more heat to the environment than the person can generate, I expect most folks elect to go with a system that is going to work most of the time and unfortunately that means that there will be times where the weather conditions go the extreme where they will be uncomfortable. The hot water bottle method is a means of stretching the comfort range by some extra amount by using gear and consumables that most would carry. Most folks carry fuel and that carries a lot of BTUs per pound. That stored energy can be quickly converted to a longer duration source of heat for a marginal sleeping bag, albeit at the potential cost of running low on fuel later in the trip. That can be offset in most areas by electing to cook with wood later in the trip.

When I winter hike I and many others carry hand warmers. They put out minimal heat for a long period yet make a significant difference in comfort. When compared to high winds and low temps I expect they contribute minimally to my survival but they do a good job in keeping my fingers warm. I also carry toe warmers and on rare occasions will use them when I have cold feet. I expect the hot water trick has a similar effect, the warm bottle is supplying a small somewhat longer duration amount of warmth to an area of the body which tends to lose circulation as the body shifts diminishing heat resources to maintaining the core temperature.

rocketsocks
12-17-2016, 13:40
In true whiteblaze fashion this thread is better than readers digest on the commode. :D

Sarcasm the elf
12-17-2016, 15:00
In true whiteblaze fashion this thread is better than readers digest on the commode. :D

I was thinking it resembled the commode itself. ;)

gracebowen
12-17-2016, 15:33
I was thinking about using a hot rock.

MuddyWaters
12-17-2016, 17:12
I was thinking about using a hot rock.thats what they did before water bottle....when everyone uncaringly made campfires everywhere and slept with wool blankets

Or sleep next to fire...

garlic08
12-17-2016, 17:44
I was thinking about usinrock.

In the commode?

ScareBear
12-17-2016, 18:55
In true whiteblaze fashion this thread is better than readers digest on the commode. :D

You take your laptop in the commode? :p

rocketsocks
12-17-2016, 20:12
You take your laptop in the commode? :pnope, I keep an old flip phone for the bathroom. :D

Engine
12-18-2016, 06:29
Another very useful option that keeps making heat all night is your dog. Or someone else's dog if yours isn't handy. If you let your Jack Russell run around and bark at imaginary intruders for about 15 minutes, then let them climb under the covers, it's crazy how much heat they produce. Just sayin' ;)

ScareBear
12-18-2016, 07:58
Standard Manchester Terriers put out a ton of heat! And, they are one of the few breeds that actually prefers to sleep touching it's master.

But....what if it is a Three Dog Night(tm)??? :D:D:D

Engine
12-18-2016, 08:33
Standard Manchester Terriers put out a ton of heat! And, they are one of the few breeds that actually prefers to sleep touching it's master.

But....what if it is a Three Dog Night(tm)??? :D:D:D

HAHA, that's where hijacking someone else's dog comes in. ;)

By the way, in the interest of keeping this discussion based on sound scientific principles, I attempted to get a core temperature from my Jack Russell so I could calculate his stored BTUs. Apparently, he wasn't at all interested in participating in the "study". :eek:

Greenlight
12-18-2016, 09:23
Most dogs aren't into science. They prefer rummaging through the trash looking for free carbs.


HAHA, that's where hijacking someone else's dog comes in. ;)

By the way, in the interest of keeping this discussion based on sound scientific principles, I attempted to get a core temperature from my Jack Russell so I could calculate his stored BTUs. Apparently, he wasn't at all interested in participating in the "study". :eek:

garlic08
12-18-2016, 12:17
Most dogs aren't into science....

But some are, according to Gary Larson:

37461

Greenlight
12-18-2016, 12:31
But some are, according to Gary Larson:

37461

+1


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sethd513
12-18-2016, 15:48
The clear plastic Nalgenes hold up to hot water a lot better than the milky white variety.

And on nalgenes site I believe the milky white ones supposing can handle hotter water. I bought them for that fact and they taste strange


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ScareBear
12-18-2016, 16:34
The milky white ones are HDPE. HDPE is somewhat porous...and even Nalgene advises that they will retain odor/taste! If you don't want that, then you go with a polycarbonate one(Lexan). Lexan is even more resistant to heat. However, it gives off BPA's. BPA's are no bueno....

pilgrimskywheel
12-18-2016, 16:58
Let's reflect for a moment on the potential benefits v risks of intentionally bringing a giant container of water into your sleeping bag with you in winter. Short term comfort v potential long term suffering? Nah.

Sarcasm the elf
12-18-2016, 17:07
Yeah, HW bottles are an absolute staple for cold weather camping, used by zillions of folks in the mountaineering community, I just plain don't see any objection if simple care is used to make sure the cap is on right and tight.

I think this is the most useful sentence posted in the discussion. This really is an accepted and longstanding practice among mountaineers. I'm not sure how much of a more solid endorsement you can get than that.

With that said, please continue arguing, I'm finding it all quite entertaining. ;)

pilgrimskywheel
12-18-2016, 17:54
con-den-sa-tion /kan,den'saSH(e)n/ noun 1. water that collects as droplets on a cold surface when humid air is in contact with it. 2. the conversion of a vapor or gas to a liquid.

Just because a thing is old - that don't make it good. This aint yer Granddaddy's hike either!

How about this one from hiking antiquity: carry a sack of potatoes (very light) and bake em around the campfire. At hiker midnight you bring em in the fart sack wid chu. In the morning you eat em for breakfast! If a bar aint et ya furst dat is!

ScareBear
12-18-2016, 18:08
Do you know why a mountaineer puts all of his water BOTTLES in his sleeping bag?

I can give you only one guess...and it aint for heat...;)

pilgrimskywheel
12-18-2016, 19:21
Lemme guess. He/she can't find springs, or snow, and carries no stove or tent cause he's a real high speed go-lighter? I don't know any big shot mountaineers. Not since my last visit up to the 10th. Mountain Division. Is there another website for them?

MuddyWaters
12-18-2016, 21:51
Let's reflect for a moment on the potential benefits v risks of intentionally bringing a giant container of water into your sleeping bag with you in winter. Short term comfort v potential long term suffering? Nah.

We can reflect on the potential benefits vs risk of driving down a road at 65 mph.
and accidentally varying 5 ft to one side.

worth it? apparently it is.

Life is never zero risk.
Most people are oblivious to the biggest risks in their life (heart disease for instance) , while focusing on minor ones.

Like bears
Being assaulted on trail
Or even a leaking water bottle.

To each...their own.:)

My personal view is that a couple extra oz of down is a better use of wt than excess fuel for boiling water however. Or sleep socks. Or sleep clothing.

garlic08
12-18-2016, 23:33
con-den-sa-tion /kan,den'saSH(e)n/ noun 1. water that collects as droplets on a cold surface when humid air is in contact with it. 2. the conversion of a vapor or gas to a liquid...!

I don't understand how this applies to this conversation. We've been talking about water in a closed bottle.

pilgrimskywheel
12-19-2016, 01:06
I don't understand how this applies to this conversation. We've been talking about water in a closed bottle.

Where's Bill Nye when you need him?

Sarcasm the elf
12-19-2016, 01:13
Where's Bill Nye when you need him?

He's off fighting crime as his superhero alter ego Speed Walker


https://www.youtube.com/watch?v=CJVBZuxTo1I

Greenlight
12-19-2016, 06:13
He's off fighting crime as his superhero alter ego Speed Walker


https://www.youtube.com/watch?v=CJVBZuxTo1I

Bill Nye the Engineering Guy?


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Sarcasm the elf
12-19-2016, 09:28
Bill Nye the Engineering Guy?


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That's the one. His improv career is what launched his career prior to being "Bill Nye the Science guy." He also has a degree and background in engineering to back it up.

garlic08
12-19-2016, 10:00
Where's Bill Nye when you need him?

I'm serious. Please pass on the snark. How does a hot water in a bottle in the sleeping bag affect condensation? Unless the extra heat helps evaporate it, as mentioned in post #40 above.

Greenlight
12-19-2016, 10:56
That's the one. His improv career is what launched his career prior to being "Bill Nye the Science guy." He also has a degree and background in engineering to back it up.

I was trying to gadfly people into a discussion over science and engineering. Scientists are usually adamant that engineers are not scientists.


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Engine
12-19-2016, 10:58
I'm serious. Please pass on the snark. How does a hot water in a bottle in the sleeping bag affect condensation? Unless the extra heat helps evaporate it, as mentioned in post #40 above.

+1

I would be interested in hearing your theory as well. Once the bottle is closed, maybe placed in a large ziplock and then inside of a sock, how is it going to have any effect on condensation? No moisture is escaping from the bottle, unlike the vapor contained in your breath and the ambient air, so what additive effect will it have?

The overwhelming majority of condensation inside your tent comes from your breath. If you don't tuck your head inside your bag and as long as you were dry when you got in the bag, there should be no condensation inside the bag when you wake up. Moisture on the outer shell of your bag is another story, and that usually occurs when you allow the bag to come into contact with the tent wall.

As has been pointed out earlier by more than one post, this method has been used for a long time by experts who regularly sleep in the extreme cold. People like Andrew Skurka (probably more trail miles than any 5 of us combined), Peter Whittaker (co-owner of Rainier Mountaineering with a summit resume too long to list), Hall, Fisher, and Brashears (all Everest guides), etc. Hall and Fisher died during the blizzard of '96 on the mountain, but that is unrelated to our current conversation.

The combined experience in just those few names is profound, and they all have advocated using this technique when it becomes necessary.

Sarcasm the elf
12-19-2016, 11:02
I was trying to gadfly people into a discussion over science and engineering. Scientists are usually adamant that engineers are not scientists.


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Ah, I thought you were making a joke about how he is "The Science Guy" but his actual degree is in mechanical engineering.
I guess I was close:D

Greenlight
12-19-2016, 11:04
I guess that working for NASA gets him close enough ;)


Ah, I thought you were making a joke about how he is "The Science Guy" but his actual degree is in mechanical engineering.
I guess I was close:D

nsherry61
12-19-2016, 11:36
I'll bite, being a scientist and not an engineer.

A useful general idea may be that scientists theorize, develop and test ideas whereas engineers apply those ideas to doing things in the real world.

This thread is addressing ideas that are engineering oriented. Science would be more of a discussion of what was measured and whether or not measurements verified our assumptions.

In this thread we haven't done any real measurements and extensive observations have largely been ignored in preference to poorly developed theory. . . with the exception of some very poignant insights from Engine and, well, also, of course, some joyful wit! Thanks!

1) It is said that a little knowledge can be very dangerous. I have noticed a lot of comments in this thread (mostly from one, apparently very "scared" poster) that have been gallant and naive attempts at scientifically arguing against water bottles in sleeping bags based on seriously flawed basic assumptions and only partial understanding.
2) There is a reason that responsible engineers, especially the really good and capable ones, ALWAYS test their ideas in the real world. Theory doesn't cut it when when real world shows beyond reasonable doubt that whatever idealized model the theory is based on doesn't measure up to experience.
3) If you are a scientist, remember, even if you are "certain" with a p=0.01, a 99% confidence, you will still be wrong some of the time (1% of the time in this case). The only certainty in science is that you will, at least some of the time, be wrong, at least if you do enough work.

Miguelon
12-30-2016, 16:16
Hey all,


So here is my Hot Water Bottle/ shower system.


103g/3.63oz


3 Liter Playtpus Hoser with drink tube taken off and cap put on in it's place. (The cap is used to keep the Hoser closed so can be used as a hot water bottle/sleeping aid. Since the Hoser is going to have hot water put into it, I don't plan to use it for drinking water. Though I could, if needed.)
55


Doc Bronners 20cc/soap/dishsoap (Dutchwear sells 20cc bottles.)
20


Orange Wash Towel
22


Shower Spout: Nalgene 1oz lid w/holes. (Little nalgene bottle lids fit perfectly onto the Hoser. Took lid, heated up needle, plunged through plastic head over and over and over again to create a little shower head.)
2


Stuff Sack that I use for this stuff.
4


(bearline and rock bag, emberlit fireant wood stove, pot, firestarter not listed in this weight.)

How I used this system last summer:
I filled hoser part way with ambient temp water, boiled water and mixed it in. Then took water out of hoser and boiled it, put boiling water into hoser. Repeat. Slowly raised temperature of water in the hoser to heat level desired. Using bearline and rock sack carefully lifted up hoser to desired height. Changed hoser lid to shower lid and showered.

To save weight a 2 Liter Platypus could be used.... and I might do just that to save 18 grams... but I like the idea of a 3 Liter shower... It's much harder to hang a 2 Liter platypus... And adding 3 liters of hot water to the sleep system would add longer lasting warmth than 2 liters.

Miguelon

ScareBear
12-30-2016, 16:53
I'll bite, being a scientist and not an engineer.

A useful general idea may be that scientists theorize, develop and test ideas whereas engineers apply those ideas to doing things in the real world.

This thread is addressing ideas that are engineering oriented. Science would be more of a discussion of what was measured and whether or not measurements verified our assumptions.

In this thread we haven't done any real measurements and extensive observations have largely been ignored in preference to poorly developed theory. . . with the exception of some very poignant insights from Engine and, well, also, of course, some joyful wit! Thanks!

1) It is said that a little knowledge can be very dangerous. I have noticed a lot of comments in this thread (mostly from one, apparently very "scared" poster) that have been gallant and naive attempts at scientifically arguing against water bottles in sleeping bags based on seriously flawed basic assumptions and only partial understanding.
2) There is a reason that responsible engineers, especially the really good and capable ones, ALWAYS test their ideas in the real world. Theory doesn't cut it when when real world shows beyond reasonable doubt that whatever idealized model the theory is based on doesn't measure up to experience.
3) If you are a scientist, remember, even if you are "certain" with a p=0.01, a 99% confidence, you will still be wrong some of the time (1% of the time in this case). The only certainty in science is that you will, at least some of the time, be wrong, at least if you do enough work.
So, as a scientist, what are my serious flaws in my basic assumptions? And, where do I lack a complete understanding. Physics? Thermal dynamics? I am curious here, since you are a scientist...

rocketsocks
12-30-2016, 18:51
I'll bite, being a scientist and not an engineer.

A useful general idea may be that scientists theorize, develop and test ideas whereas engineers apply those ideas to doing things in the real world.

This thread is addressing ideas that are engineering oriented. Science would be more of a discussion of what was measured and whether or not measurements verified our assumptions.

In this thread we haven't done any real measurements and extensive observations have largely been ignored in preference to poorly developed theory. . . with the exception of some very poignant insights from Engine and, well, also, of course, some joyful wit! Thanks!

1) It is said that a little knowledge can be very dangerous. I have noticed a lot of comments in this thread (mostly from one, apparently very "scared" poster) that have been gallant and naive attempts at scientifically arguing against water bottles in sleeping bags based on seriously flawed basic assumptions and only partial understanding.
2) There is a reason that responsible engineers, especially the really good and capable ones, ALWAYS test their ideas in the real world. Theory doesn't cut it when when real world shows beyond reasonable doubt that whatever idealized model the theory is based on doesn't measure up to experience.
3) If you are a scientist, remember, even if you are "certain" with a p=0.01, a 99% confidence, you will still be wrong some of the time (1% of the time in this case). The only certainty in science is that you will, at least some of the time, be wrong, at least if you do enough work.One not need be a sciencetist to understand some basic scientific principals...like having a bottle filled With water and applying a small force while it creates a huge force enough to pop off a cheapo water bottle cap...and to extrapolate that it's a far inferior product as opposed to a product designed to take a lickin' and keep on tickin'
eh hmm "Nalgene" high density poly ethylene.

rocketsocks
12-30-2016, 18:53
...you don't even need be a good schpeller, just some common sense.

Engine
12-31-2016, 08:18
So,as a scientist, what are my serious flaws in my basic assumptions?And, where do I lack a complete understanding. Physics? Thermaldynamics? I am curious here, since you are a scientist...

We can start by looking at your earlier quote related to exposure time and resulting third degree burns. The figures you quoted are for direct skin exposure to heated water. As we all know, water is extremely efficient at transferring heat, while the air and solid objects are typically much less so, with the exception of some metals. Hear is your earlier quote:


... OMG....Iwas going to say it isn't rocket science...but...look...you can't puta water temp greater than 140F in the water bottle or you will causea third degree burn in SIX SECONDS. 130F? THIRTY SECONDS TO THIRDDEGREE BURNS. 120F? FIVE MINUTES TO THIRD DEGREE BURNS! You've seenan egg cooking on a sidewalk,right?
http://www.accuratebuilding.com/services/legal/charts/hot_water_burn_scalding_graph.html (http://www.accuratebuilding.com/services/legal/charts/hot_water_burn_scalding_graph.html)

You were correct, it isn't rocket science, here is some interesting information from Sunbeam which is actually applicable to the temperature discussion:

“If you use one of our Soft Touch or HeatSenseTM heating pads, you may choose a temperature from the following settings: Lo: 110F Medium:138F Hi: 160F Healthat Home heating pads are engineered to never exceed 176F, thetemperature limit set by Underwriters Laboratory.”




My admittedly pseudo-scientific test:


A few days ago, after this discussion got going in earnest, I tested the theory in my kitchen with a 16 ounce Lexan Nalgene bottle, aheavy wool sock, and a meat thermometer probe. After pouring boiling water into the bottle and tightly capping it, I stuffed it into the sock, laid it on a bandanna, and taped the probe over the top of thesock. I then laid a second wool sock over the top of the whole thing to mimic being under a sleeping bag. Although I feel the sleeping bag environment would be much more efficient. The ambient temperature in the room was 72*.


Within 5 minutes the probe read 113*


After 30 minutes, it read 131* (approximately equal to medium on a heatingpad...)


After 60 minutes, it read 123*


After 90 minutes, it read 116*


After 120 minutes, it read 109* (approximately equal to the low setting on a heating pad)


After 150 minutes, it read 105*


After 180 minutes, it read 100*


At 183 minutes, it dropped to 99* (I stopped the test, although it was still warm to the touch and obviously warmer than my external skin temperature at that time).


I have photos of the temperature readings from the test, should anyone care to verify these numbers.


It's important to remember, I used a 16 ounce Nalgene, not the 32 ounce bottle typically recommended for this practice. Science tells us the surface area to mass ration has a direct linear relationship to heat loss, with a lower surface area to mass yielding increased thermal retention.


The surface area of the 16 ounce bottle used for the test is 68.03 square inches, giving a surface area to mass ratio of 4.25 sq/in per ounce.The 32 ounce bottle is 109.96 square inches, yielding a ratio of 3.43sq/in per ounce.


The 32 ounce Nalgene has twice the stored energy and only 80.7% of the surface to mass ratio. It will release two times the energy over approximately 20% more time. Since the 16 ounce bottle lasted 183 minutes, it's reasonable to extrapolate a useful time of 219 minutes for the 32 ounce bottle. Given that twice the energy will be released in less than twice the time, the temperatures will certainly be higher than those achieved by the 16 ounce bottle. But given the Underwriters Laboratory maximum of 176* for a heating pad, it's highly doubtful the temperature through a sock would ever get too hot for the intended use.


Sorry this was so long winded, but let ask a question. When the temperature gets really low while trying to sleep, would you welcome a heating pad set to low or medium in your sleeping bag, even if only for 3-4 hours? The 32 ounce bottle might even let you enjoy a heating pad set to high...at least for awhile.

MuddyWaters
12-31-2016, 09:03
One not need be a sciencetist to understand some basic scientific principals...like having a bottle filled With water and applying a small force while it creates a huge force enough to pop off a cheapo water bottle cap...and to extrapolate that it's a far inferior product as opposed to a product designed to take a lickin' and keep on tickin'
eh hmm "Nalgene" high density poly ethylene.



Soda bottles burst at about 100 psig. Take about 80 with no problem repeatedly, without leaking .

Can a large lid, flat sided, nalgene do that?

Doubtful

The increased sealing surface in wide mouth nalgene, and more rigid materials, actually decreases sealing forces and ability.

There may be temperature limitations or such, and some water bottles may be quite flimsy, but I think assuming all non-nalgene bottles will leak because they arent heavy nalgenes is conjecture, with little evidence to back it up. And quite possibly flawed.

pilgrimskywheel
12-31-2016, 11:44
Incredible! How Bill Nye, I mean SW, is able to achieve those speeds safely without poles or a gallon of hot water to maintain homeostasis is perhaps science from Thor's world! Was that a Ruger Mark II firing 7.65 cartridges? That's even hotter than a Nalgene full of fluid - and lighter! I gotta get one of them - for when my bear can fails. Did you notice he saved all them folks and didn't even ask for a single donation to keep going? Thanks Speed Walker - we love you!

rocketsocks
01-01-2017, 03:50
Soda bottles burst at about 100 psig. Take about 80 with no problem repeatedly, without leaking .

Can a large lid, flat sided, nalgene do that?

Doubtful

The increased sealing surface in wide mouth nalgene, and more rigid materials, actually decreases sealing forces and ability.

There may be temperature limitations or such, and some water bottles may be quite flimsy, but I think assuming all non-nalgene bottles will leak because they arent heavy nalgenes is conjecture, with little evidence to back it up. And quite possibly flawed.
Well I don't know about all that, and I have no plans what so ever to preform a test cause quite cranky...I could care less, :D but if you take a water bottle fill to the brim and squeeze it your generating way more than 100 psi hydrostaticly speaking, and if I were to step on it I'll shoot the cap right off. Now I'm not suggesting the Normal sleeper with night terrors is gonna some how get in a all out donnie brook with there water bottle while in there sleeping bag, just that a nalgene will likely not pop its top if ya kick it in your sleep.

rocketsocks
01-01-2017, 03:56
Well I don't know about all that, and I have no plans what so ever to preform a test cause quite cranky...I could care less, :D but if you take a water bottle fill to the brim and squeeze it your generating way more than 100 psi hydrostaticly speaking, and if I were to step on it I'll shoot the cap right off. Now I'm not suggesting the Normal sleeper with night terrors is gonna some how get in a all out donnie brook with there water bottle while in there sleeping bag, just that a nalgene will likely not pop its top if ya kick it in your sleep.youll shoot the cap right off
...or at least split the bottle.

la.lindsey
01-01-2017, 14:06
Oh my god. I don't even know what yall are talking about now, but you do know that generally you can run over a nalgene and it won't break, right? I don't think squeezing it in your sleep will cause the top to pop off.

Actually, I know it won't, because I do this all the damn time, including last night, without a stupid wool sock over it, and I'm not dead yet and I don't have 3rd degree burns and my sleeping bag isn't a wet mess and I haven't gotten BPA cancer and it lasts from about 7:30pm until 4am or so, if I do absolutely boiling water and fill the entire bottle. Can't give you an exact time because I'm quite happily warm and asleep.

Good lord.

Sincerely,

A freezing, cold-sleeping mechanical engineering student who trusts her tools. And also knows how thermodynamics works. Condensation, really?


Sent from my iPhone using Tapatalk

garlic08
01-01-2017, 14:13
Good Lord, indeed! I don't know what happened to this thread in the last day, but it sure got weird.

Happy New Year, all.

Greenlight
01-01-2017, 15:34
Oh my god. I don't even know what yall are talking about now, but you do know that generally you can run over a nalgene and it won't break, right? I don't think squeezing it in your sleep will cause the top to pop off.

Actually, I know it won't, because I do this all the damn time, including last night, without a stupid wool sock over it, and I'm not dead yet and I don't have 3rd degree burns and my sleeping bag isn't a wet mess and I haven't gotten BPA cancer and it lasts from about 7:30pm until 4am or so, if I do absolutely boiling water and fill the entire bottle. Can't give you an exact time because I'm quite happily warm and asleep.

Good lord.

Sincerely,

A freezing, cold-sleeping mechanical engineering student who trusts her tools. And also knows how thermodynamics works. Condensation, really?


Sent from my iPhone using Tapatalk

Thank you. Go girl!


Sent from my iPhone using Tapatalk Pro

pilgrimskywheel
01-01-2017, 15:34
Meanwhile, back at the laboratory... Hey Scare Bare, could you please post the pictures of your temperature readings for verification. I've repeated this experiment 8 times in the last 72 hours and my stats just don't jive. I think I'm not generating enough gigawatts from the flux capacitor. I'm not reaching 1.21 as my electrical sources aren't quite strong enough, and I can't get a solid strike on my Franklin Rod to do it. Thanks

Engine
01-01-2017, 16:21
Meanwhile, back at the laboratory... Hey Scare Bare, could you please post the pictures of your temperature readings for verification. I've repeated this experiment 8 times in the last 72 hours and my stats just don't jive. I think I'm not generating enough gigawatts from the flux capacitor. I'm not reaching 1.21 as my electrical sources aren't quite strong enough, and I can't get a solid strike on my Franklin Rod to do it. Thanks

Actually I posted that, here are pics.

37729 Initial pic showing temp at 5 minutes without the cover sock laying on top.

37730 Pic at 30 minutes, note send sock laying on top as noted.

37731 60 minutes

37732 90 minutes

37733 120 minutes

37734 150 minutes

37735 180 minutes

37736 183 minutes

pilgrimskywheel
01-01-2017, 16:44
Fascinating. Thank you seriously. I laud your efforts to support good hiking science. I've used this method with mixed results. I started my 2012 thru-hike on January 6, 2012 and spent four days waiting in a storm at the Black Gap Shelter. (I needed the time as I had walked up RT19 from Hotlanta with 3 cracked ribs, a cauliflowered ear, and a recent concussion, courtesy of the Ocala PD - who don't know what thru-hikers are, and really have no sense of humor whatsoever!) It indeed is a great way to keep your canteens from freezing, and your aggies warm - to a point. I found waking up for the 3am patrol the time to move my not-so-hot bottles out, and then lay there a bit cooler waiting for pre-nautical twilight, which as you know is late that time of year. It drove fuel consumption up to a point where it made me nervous. I felt better acclimatized forgoing this method in future, especially after taking the leap of faith to sleep in my birthday suit which is incredibly hot - thermally that is.

pilgrimskywheel
01-01-2017, 17:02
Oh, sorry I forgot - when the bottles get cooler than you are (you being at about 100 degrees) they tend to sweat a bit. They get slimy, slick, then wet. This, as all our intrepid engineers will I'm sure testify to, is process called condensation. The change of water from a vapor to a liquid that collects as droplets on a cool surface when humid air is in contact with it. And, if you've never camped someplace so cold you have to keep your face in the bag, you have no idea how this might happen. While using a sock as a prophylaxis against this is awfully clever, I prefer mine bone dry in the morning. Condensation is probably best exemplified by my iced cocktail currently beaded in in water droplets somewhere nice and toasty below the sun line where winter doesn't happen. Old Mrs. McNulty would be so proud I stole her example from freshman science class just then.

RobertThePilgrim
01-09-2017, 11:06
I was trying to gadfly people into a discussion over science and engineering. Scientists are usually adamant that engineers are not scientists.
Engineers are not scientists, scientists are not engineers.
It is not uncommon for members in one profession to dabble in the other, not always with pretty results :)

RobertThePilgrim
01-09-2017, 11:24
Sorry I'm a little late to the show, just wanted to share a couple of thoughts...
For me, the two temperature ratings for sleeping bags that I am most interested in are the temp at that I can sleep comfortably for 8 hours (call it the comfort rating) and the temperature at which I can sleep for 6 hours without becoming hypothermic (call it the extreme rating).
(Above definitions/names are borrowed/modified from the European sleeping bag rating (EN13537) but parallel my much less well defined feelings on the subject.)

IMHO:
When packing in the middle of nowhere, planning a trip where you might get close to the extreme rating is a seriously Bad Idea(TM).

For a long trip while simultaneously within no more than a few days hike of civilization, the availability of a hot water bottle to get a solid 5 hours of sleep without frostbitten toes would make using a substantially lighter bag an acceptable risk, and if the weather did not become extreme, the hot water bottle would make that lighter bag comfortable to sleep in on cooler nights.

For the considerable proportion of the population that gets cold feet a hot water bottle could easily (and by the testimony of an earlier post, does) make the difference between a comfortable nights sleep and a restless night. Beyond the comfort, that better sleep means being more alert the next day which can be a significant safety factor.

RobertThePilgrim
01-09-2017, 11:36
And just because I like to play with numbers...
Put the sock covered bottle between the sleeper's feet and the sleeping bag.
Ts = temperature of sleeper
To = temperature of outside
Tb = temperature of bottle
iso = insulation between sleeper and outside
isb = insulation between sleeper and bottle
ibo = insulation between bottle and outside

Skin temp for feet is generally under 90degF, for the torso it is around 92degF.

The heat flow from a person through a sleeping bag to outside* will equal
heat flow from person through sock to bottle occurs when:
(Ts - To) / ipo = (Ts - Tb) / ipb
solve for Tb:
Tb = Ts - (Ts - To) * ipb/ipo
plug in some numbers:
= 90 - (90 - 20) * 1 / 10 (yes, ipb/ipo = 1/10 is a WAG, better numbers are hereby solicited)
= 83degF

Assuming a starting temp of 203degF, that means that a 1 liter bottle of water has 66 kcal of energy to give up.
Engine cited 315 BTU/hour = 635 kcal/night for energy production by humans, I found values from 400 - 760 kcal per 8hr night.

So, as Engine stated roughly 15% for 5 hours. Most of this during the time when the would-be sleeper is attempting to warm up the sleeping bag, in particular around the feet.

Do note that since the bottle is effectively additional insulation, it will never suck heat away from the sleeper.

*Not through the entire sleeping bag, just through the part of the sleeping bag that the water bottle is covering up.

http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2010.197517/full
3.5-4.5 kj/min (~ 50-65 kcal / hour) = max 520 kcal / night

other sources claim 95 kcal/hour (= 760 kcal/night) without any citations.

http://hypertextbook.com/facts/2001/AbantyFarzana.shtml cites various sources
http://www.healthyheating.com/Definitions/facts_about_skin.htm
which cites:
Olesen, B.W., 1982, Thermal Comfort, Technical Review, Bruel & Kjaer