View Full Version : New Women's Sleep bag? Sleeping cold
barefoot
10-22-2009, 10:07
My 22 year old daughter last year bought the women’s Northface Cats Meow. It’s a 20 degree bag filled with Climashield Prism synthetic insulation. She loves the fit, etc but it doesn’t keep her warm. Last weekend we were in 38 degree NC weather and she was cold the first night and had to add multiple layers of clothes the second night. The past several trips we have been in mid 30s and she has been cold.
So we want to exchange the bag. If she gets another 15-20 degree bag but with down would that make a difference or do we even get a 0 degree bag for her?
Many things can lead to sleeping cold such as being dehydrated (and not knowing it), sleeping in wet or dirty clothes, sweating in a bag, not having enough to eat late enough, or even having a full bladder (it takes a lot of energy to keep all the fluids warm).
But what is often the case with womens bags, and is such with The North Face, is that even there women's bags are sold using "men's" ratings, while women actually sleep colder than men (as a general rule, obviously everyone sleeps different, some hot, some cold, some neutral).
What might help is to look at the EN 13537 Ratings. These ratings are standardized tests for bags sold in Europe (in the US we have no standard rating system which is why so many bags are so off on the temp rating). If you go to TNF's Europe site you can see that the Women's Cat's Meow is rated at 19.4*F for the average man, but only 32*F for the average woman.
For help with the EN rating system, let me explain that they will give 3 diffrent tempreture ratings. The first is the "Comfort" ratings. This is what I call the "Womans" Rating because that is the coldest temperature pthat the average woman will be able to sleep comfortably. The next is the "Lower Limit" which is what I call the "mens" rating. It is the coldest temperature that the average man can sleep comfortably. The last, and most useless rating is the "Extreame" Rating. This is the coldest that the average woman can stay in the bag without bodily injury (ie frostbite). Obviously, you never want to go near that rating, and it is useless for purchasing bags in my opinion.
Mountain Hardwear and Marmot are two manufactures that publish the EN rating on their US site (they don't always rate their bags appropriately especially for women so look at the EN rating) but for other manufactures you might have to go to their European site which isn't always easy to find.
Is there any reason why you went with a synthetic bag over down? For example you can get the Womens Marmot Pinnacle which is Comfort (women) rated to 21.6*F and weighs 2lb 4oz.
Another thing to look at may be the sleeping pad. Many people overlook the pad when looking for a reason they are sleeping cold. What kind of pad was she using?
Ratings can vary from manufacturer to manufacturer, but within the same manufacturer a 20 degree rating should equal a 20 degree rating, at least in theory. Here are some other considerations.
1. Two sleeping bags of the same loft should have approximately the same rating, regardless of material, all else being equal (see 2,3 below).
2. If a sleeping bag allows alot of air leakage around the head and neck area this can be more comfortable in summer, but will make the bag considerably colder. Conversely more claustrophobic designs will be warmer and more comfortable in cold weather, once you get comfortable sleeping in them. For 35F and above more open designs are appropriate, though heavier to achieve the same warmth.
3. Oversized bags are heavier for the same loft, and also colder for the same loft, because they have more surface area, and more room inside than ideal for heat retention, though they are more comfortable and less claustrophobic. Another way of saying this is that undersized people need smaller sleeping bags to be just as warm with the same amount of loft.
4. Well below freezing the air you breath can make a huge difference, but in the mid 30s it should not, though sleeping inside a tent will still be considerably warmer.
5. It is good to have some extra room inside the sleeping bag so that you can try varying amounts of clothing or liners to adapt the sleeping bag for different conditions. Most nights, it is best to use less clothing. For cold nights, some dry clothing or sleeping bag line can provide extra loft and also capture and recyle some latent heat from your body moisture. Aim for most nights with less clothing, but cold nights with extra clothing, if dry. Hot water bottles are also very useful. Socks, mitts, and hats make a huge difference for many people.
6. Ground pads can make a huge difference in warmth, both my providing extra insulation, and also by avoiding condensation of alot of moisture in your sleeping bag fill.
7. In theory all people generate the same amount of heat per surface area, but in practice everyone generates more heat on a full stomach, and I think some people are conditioned to generate some more heat when cold. The less well understood difference between 'warm sleepers' and 'cold sleepers' however is that 'warm sleepers' are conditioned to sleep comfortable with colder skin surface temperatures, which enables them to produce less moisture when sleeping, reducing latent heat loss, and also enables them to use the outer layer of skin as an extra layer of clothing. In practice this only amounts to saving them about 1/2" of loft, and in some ways can make them more vulnerable in extreme conditions.
8. At the end of the day everyone needs to test things to see what works for them, in keeping them comfortable on most nights, and keeping them alive on extreme nights.
In summary, its a combination of the right fit, some adaptation, some tricks, and some trial and error.
When getting to know yourself and your sleeping bag, its helpful to carry a thermometer so you can more objectively compare what works on some nights with what didn't work on other nights. Quite often it is alot colder in the morning just before dawn, but other times it can actually warm up during the night so it is easy to think your sleeping bag worked very well or even too well, when in fact it might have just been a warmer night than you thought it would was.
I will second the thermometer. Depending on how you got the 38* temp, it could have been colder (if you got it from a website etc, it might have been different at elevation or even if it was a thermometer you had, it might have been colder at night then when you checked it in the morning)
barefoot
10-22-2009, 12:02
I'm enjoying the comments. My daughter uses the small Therm-a-Rest ProLite Plus. We didn't have a thermometer but according to the weather for the area the low was suppose to be 38. I know that there are a lot of things that will effect the temps in the woods. I was using a 30 degree bag and I was fine. You couldn't see your breath, no frost, etc. I doubt that it got below freezing. We are in a tent. But her coldness has been on several trips not just this one.
The Prolite Plus should have been plenty warm for those conditions, but you said it was a small. Did she have anything under her feet? It may be that she just sleeps cold.
barefoot
10-22-2009, 16:14
She is only 5'4" so she fits on her pad
take-a-knee
10-22-2009, 16:35
She needs to see the doc and get her thyroid checked, that ain't normal. A Cat's Meow is a solid 20F bag. A lot of smallish females sleep 10 F colder, but not cold at 18F above the bags' rating. She's a hypothermia case waiting to happen.
But the bag is only rated at 32* for the "average" female, and you don't know exactly how cold it was on the night in question at that elevation etc.
garlic08
10-22-2009, 18:16
I changed my bag from the 20 Campmor to the 15 Marmot Helium, and there was a heck of a lot more than 5 degrees difference in my perception of warmth, more like 20 degrees. So maybe a different bag would feel warmer, but buying a new bag is an expensive way to experiment. Good luck.
The hypothyroidism is an interesting idea, and there will be other symptoms as well.
Trailweaver
10-22-2009, 22:09
I have the Cat's Meow bag and I also have been cold at temps in the 30's with it. There is nothing physically wrong with me. . . I just sleep cold, and that bag doesn't make the rating. I've been thinking of a down bag ever since my first cold night out with the Cat's Meow.
I also have used the Cat's Meow, am a 5'4" female and sleep cold in cool weather, no matter what. After wrestling with the weight of the bag and how much I wanted to carry to stay warm, coupled with the fact that it took alot to keep me warm, I went with down. I have a WM Ultralite (I think that's what it is, I've had it for several years now.). I've never had a problem keeping it dry, due its being down. Packs nice and light and, best of all, I've never had a cold night in it, in spite of being out in some very nasty weather. I sleep on a green thermarest pad (also have had that for years, don't know the rating, sorry)...but these things have worked for me, despite that I am just a cold sleeper.
cowboy nichols
10-23-2009, 07:42
Silk,underwear-long john type and a silk liner Plus down booties in very cold weather works for me.
Brushed nylon sleeping bag liner makes a sleeping bag feel much warmer for me.
The usual nylon sleeping bag fabric just feels cold.
But for her to be cold, in the conditions you describe, would tend to indicate a thyroid problem. Really. I think so.
Did she have some hot food before getting in the sleeping bag?
All the suggestions here are good. I would only add a "collar" inside the bag, part of the design of many cold-weather sleeping bags, makes a big difference in staying warm.
I also have used a "rebreather" face mask for cold weather and for keeping "condensation" to a minimum.
I like the PSolar.EX facemask or the PolarWrap Warm Air Mask, Full Head Cover or ExChanger II, because these specially prevent having to heat cold air at every in breath.
If it means not going at all, you might consider trying the PolarWrap Warm Air Mask, for example.