Cold feet

[Bearbait]

I ran into a little problem the other night. The temperature droped down to 32 or 33 degrees and my feet got really cold. The rest of me was fine. I was using a Moutainsmith 20 degree bag. This is my first time to camp in cold weather so what are some good tips for staying warm????

[Skeemer]

I always took an extra pair of socks to wear in bed only. Kept feet warm and bag cleaner. Also served as "emergency back ups"

[Former Easy]

I ran into a little problem the other night. The temperature droped down to 32 or 33 degrees and my feet got really cold. The rest of me was fine. I was using a Moutainsmith 20 degree bag. This is my first time to camp in cold weather so what are some good tips for staying warm????

You might have had to many clothes on, believe it or not your bag stays warmer and generates more heat with the less you wear. You should have been fine in a 20 degree bag in 32 degrees. I have slept in my 20 degree in weather all the way down to 6 below (once) and many times when it was around 10 degrees. My bag isn't as good of qualty as a Mountainsmith either.

[Repeat]

One of the most important pieces of equipment I take on cold weather trips is a pair of insulated booties for use arround the camp. Once at Icewater Springs when the temp was -5 F- I wore them in my sleeping bag. They really improve my comfort level in cold weather. The following are links to a couple of different products.
http://www.campmor.com/webapp/commerce/command/ProductDisplay?prrfnbr=33049206&prmenbr=226

http://www.backcountrystore.com/store/SDS0076.html

[Lilred]

You might have had to many clothes on, believe it or not your bag stays warmer and generates more heat with the less you wear. either.

This is true. I did a section in Nov. with a 20 degree bag from Campmor. The temps got very cold at night and I ended up having to take my socks off because my feet were so cold. Soon as I took them off, my feet warmed up and I was fine. Also, if you're using a 3/4 length sleeping pad, having your feet dangle off will cause them to be colder, especially if you're in a shelter. I stuck my boots or pack under my feet and that seemed to help too.

[Alligator]

If changing your layering or adding insulated booties does not help, chemical warmers are a nice alternative. The weight can add up though.

[Bankrobber]

I know this sounds silly, but make sure that you empty your bladder as much as possible before you go to sleep. It takes extra energy to keep excess liquid heated to body temperature.

[Bearbait]

I wondered about the cloths. I'm embarraced to say, but I had on thermals and a jogging suit on in my bag. Up until now the coldest temp i've slept in was in the 40's. I'm planning another trip Saturday 27th. It's supose to be in the mid 30's. I will try less clothing. There will also be several packs of hand and foot warmers in the backpack just in case. Thanks for the advice.

[Frosty]

I know this sounds silly, but make sure that you empty your bladder as much as possible before you go to sleep. It takes extra energy to keep excess liquid heated to body temperature.

I've heard that the body loses most heat through the head and extremities. I've never heard that internal organs are a major source of heat loss. The only heat the body has to supply is that heat which is lost, and heat is lost by contact with air or cold surface. There is no heat required to "keep warm." A body will stay the same temp unless heat is lost. Seems like semantics, but this is an important thermodynamic point.

Besides, if heat loss were a function of the amount of weight one had to "keep warm," then the lighter a person was the warmer they'd be: a forty pound child would never got cold, and a 400-pound person would freeze to death in 31 degree temps.

Even if it were true, the amount of heat required to keep 8 ounces of liquid warm would be meaningless compared to the weight of your body.

All that said, there is an important reason to empty the bladder before crawling into a sleeping bag, and that is to avoid getting up and going outside to pee in the middle of the night.

[Alligator]

Hey Frosty,

The whole body will lose heat at different rates at the surface, not just the head and other extremities. It all depends on the clothing. The reason hands and feet get cold is because if the body senses excessive cooling, it starts to close down heat transfer to the extremities in order to protect the core of vital organs. Heat loss still occurs at the legs, back, etc, but is usually much less because of jackets and pants. The body is constantly losing heat when conditions are colder than body temperature. A thermal scan of a person would still show heat loss around the whole body. Since heat radiates from hot to cold, new energy needs to be used to maintain the body. Internal organs still need to generate heat to resupply the heat being lost across the body.

The amount of energy an object/material/substance can store per unit weight is called the specific heat capacity (If I am remembering my chemistry terms correctly). Water has a high specific heat capacity. Thus it stores energy well. Having a mass of urine in the bladder requires the addition of energy to maintain a specific temperature. Voiding this mass lessens the total mass of the body, thus requiring less energy to maintain the body's temperature. How much, a lot, some, a little, I've never done the calculations, but I have seen this tip presented by very experienced winter hikers. Getting up in the middle of the night to go is also a very high heat loss, so some folks will suggest the addition of a pee bottle.

There's more going on with the little and big people, such as surface area to volume ratio and capacity to generate heat. The big person has a bigger "furnace".

[Colter]

I've heard that your body produces about as much heat as a light bulb. To put it simply, to stay warm you need to trap enough heat so you don't have a net loss.

I'm no Roald Amundson, but I've spent scores of nights sleeping out in subzero temperatures, down to -50 or colder in Alaska. Lots of the information about keeping warm that you read on the internet is wrong. One of these "facts" is that if you are too cold you will stay warmer by sleeping nude or taking off clothes. That is simply untrue UNLESS you put on so many clothes that you squash the insulation in your sleeping bag flat or your restrict your circulation. (You need good circulation to stay warm, which is why if you pile on too many socks in warm boots you will ruin your circulation and get cold feet.) Few folks have sleeping bags with that little room in them. I have always found that the more clothes I added the warmer I was, just like during the daytime. The warmest, day or night, is many layers of loose clothing/insulation/sleeping bag.

You will sleep warmer in dry clothes, of course. So if you have dry clothes to slip into before you go to bed, that's great. Having a warm enough sleeping bag is, of course, a no-brainer. Using a sleeping pad is very important in cold weather. You can lose an enormous amount of heat by conduction to the cold ground.

The "truism" about losing most of your heat through your head is partially true, and that is because many of us have a marginal hat with a bare neck and face. Needless to say, if you have lots of bare skin in this area you'll lose tons of heat. One of the most important items to carry for cold weather sleeping is a balaclava which should cover your whole head except for your eyes, nose and mouth. Your sleeping bag should have a hood on it, too, and in really cold weather the only thing sticking out should be your mouth. Although I often breath into my bag at first to help warm it up, breathing into your bag all night will put lots of moisture into it.

As someone said, if you have a 3/4 length sleeping pad, putting your pack or shoes underneath your feet will help keep your feet off the cold ground.

You'll get maximum warmth out of your clothing by wearing it, but if it's too confining and you have extra room in your bag, lay it over you inside the bag. If it won't fit in the bag, lay it over you outside the bag.

If it's really cold, a great thing to do to start out warm is to fill a canteen with hot water. Wrap it up in an spare article of clothing and put it by your feet and it will radiate lots of heat for the first couple of hours.

I will ALWAYS wear socks in my bag in cold weather. Booties are even better if they'll fit in your bag. The only potential advantage I can think of of starting out with bare feet is so that your initially cold feet can be warmed up by your warmer body. Otherwise, wear your warm socks!

[bearbag hanger]

I ran into a little problem the other night. The temperature droped down to 32 or 33 degrees and my feet got really cold. The rest of me was fine. I was using a Moutainsmith 20 degree bag. This is my first time to camp in cold weather so what are some good tips for staying warm????

I managed to freeze my feet back in March 1997. It got down to below 19 degress. The next night the solution came to me while boiling water for my dinner. Boil a quart of water, put in a quart nalgene bottle (a pint size would probably work almost as well), wrap in something like a polar tech jacket or whatever you have handy, put in bottom of sleeping bag. Be sure to shake up the bottle a bit and then retighten the top BEFORE you put it in the sleeping bag. Maybe I shouldn't say this, but don't touch bare bottle with bare feet. It really hurts. The boiling water bottle is not something you want to do all the time, but it can help when everything else has failed.

As always, try this at home first. Not all water bottles can handle boiling water. The lexan nalgene bottles work pretty good, the soft ones not so well.

Another thing I found, besides what has already been sugested, is try to elevate your feet a little. That will allow the warm air in the sleeping bag to go "up" to your feet.

[hungryhowie]

In colder climes, I carry a pair of fleece socks for sleeping in at night. They weigh far less than an extra pair of wool socks, and worn over my wool socks, will nearly always dry them before morning.

-Howie

[The Wicked Lobstah]

I know this sounds silly, but make sure that you empty your bladder as much as possible before you go to sleep. It takes extra energy to keep excess liquid heated to body temperature.

Not silly at all. And don't forget yer bowels. Your body spends energy keeping that poo at 98.6 too.
Also eat something. those extra calories can keep your internal furnace running a little warmer.