Sleeping bags and clothing?

C_Claycomb

C_Claycomb

Joined
Dec 11, 2000
Messages
1,044
Hi,

Was just wondering, when it is cold, and you are gonna have to sleep on the trail, what do you wear when you get into your bag?

Yeah, I know that sounds a weird question, but there is something behind it. When staying in an unheated outbuilding last winter I had a big thick duvet on my bed, this was very cold at the start of the night, but warmed up after a while and worked okay until I tried wearing extra warm PJs and fleece socks as well. When using the extra warm clothing the bed stayed icy cold all night, and by morning so was I. Does this apply to sleeping bags too.

Sorry for the random nature of this. :)

Chris
 
The less clothing you wear the better your sleeping bag should work, assuming its insulation rating is matched to the temperature. Most clothing (unless polarfleece or some similar synthetic designed to let moisture pass through) will accumulate moisture. Cotton is especially bad for this. When your clothing gets wet, your sleeping bag can't insulate you properly and that's why you get cold. So less is best. You also need adequate ground insulation. An 'intimate other' is also great in cold weather:) .
 
i dunno if u guys have them over there. but here in australia, everyone wears stretchy polypropelyn thermals as a first layer. it wicks perspiration away from the body(a dry bod is a warm bod) and absorbs almost no moisture.
 
I actually prefer camping in cold weather. That is, as cold as the temperate zone of Ohio has to offer. I sleep in my skivvies in my bag (currently a mid-line 15 degree Slumberjack), but with my clothes in there with me. If they are dry, I sleep on top of them. If they are damp, they go on top of me or get skrunched down into the foot of the bag. The latter case is very rare because usually, by the time I'm turning in, I've sat at fireside for awhile and dried out. I've always stayed comfortable, and had toasty clothes to put on when it came time for the "twilight tinkle" in the morning.
 
I second the "less is best" rule. My friends always scoff at me as they crawl into their sleeping bags wearing thick wool socks, long johns, sweats, a T-shirt, and whatever else they feel like piling on. Meanwhile I dress down to my skivvies - even in very cold weather - and crawl into my icy bag. By night's end they have not slept a wink, while I hardly want to wake up from my pleasant dreams. They still don't get it. If I'm camping alone or with my wife I usually forego the skivvies, as well. :D

This was discussed on this forum before, and as I recall there was mention of a small, lightweight bag liner that was suggested for those who sleep in little or nothing. It keeps your bag from getting all oily and dirty, thereby preserving the loft and the life of the bag.

A second benefit to wearing less: you have greater ease of movement while you sleep. If I wear pants or a shirt to bed I get all twisted up in my clothes and end up just taking it all off, anyway, so why bother. The only items I wear for protection from the cold when camping are occassionally a pair of socks (on the very coldest of nights) and a shirt worn around my neck, but not pulled down over my arms or body. The shirt helps to keep the cold air out where it belongs instead of sneaking into my bag whenever I roll over.

Sorry my reply is so long.
 
I like microfiber polyester (Coolmax, Silkweight Capilene, etc.) in the bag, but I'm thinking about trying Merino wool. www.arktisusa.com sells some that are WAY cheaper than SmartWool and Nomex treated :cool:
 
I prefer to sleep as undressed as possible, even in cold weather, but don't like the feeling of nylon against my skin. A sleeping bag liner might be just the ticket. I'm going to have to take a look at those.
 
I prefer the less is best idea. But either way I think it is a trail and error method for whatever bag you have. A 40 degree bag is cold at 28 degrees and a 28 degree bag is hot at 40 degrees. Once you have a bag, try it out in your backyard a few times and work up a system for different weather now before you really need it. Just don't do as I just did this past weekend! I had a lightwieght bag in the mountains, but I had planned well! Knowing it was going to drop to below freezing, I had taken some "poly" long johns to make up the difference. Sitting on top of the knoll in the woods I started getting ready to call it a night when I realized I had packed two tops and no bottoms.
 
I carry a lightweight down mummy bag. Although I prefer to wear as little as possible, I bought a bag large enough to allow me to wear my lightweight Primaloft jacket inside the bag if need be. That boosts the comfort rating significantly. I also chose a bag with a full-length zipper. I could have saved a few more ounces by going with a bag with a half or three qquarter zipper, but I wanted to be able to open it up and use it as a quilt in warm weather.
 
One little thing I forgot. You might want to carry a "watch cap" or tobaggan with you. A little something on your head can make a lot of difference in heat loss. Those old night caps shown in old photo's and movies had a logical use other than looking silly.
 
Wow, some response. And there I was thinking it was a real dumb question :) Wearing less to keep warm is sort of counter intuitive though!

It really was a random question, but all the extra information you guys have volunteered will help as I shop for my first bag. Thanks!

Chris
 
Originally posted by C_Claycomb
Wearing less to keep warm is sort of counter intuitive though!
Click to expand...

A little more info might help eliminate some of the mystery. By wearing less you allow your body parts to share heat with each other and to warm the air space inside the bag. Clothes trap your heat against each individual extremity, thereby cutting down on shared heat. Once you grasp this concept it will become more intuitive to strip down than to dress up.
 
Yeah, I had worked that out, more or less, based on my cold bed episode. It is the same as using mittens rather than gloves in real cold weather. Just wasn't sure whether it really did translate to sleeping bags too. Makes sense when you think about it...but you gotta think! :D
 
Dressing inside a bag is more like using gloves INSIDE mittens, nobody has yet explained how that would lead to MORE heat loss, I would like to see a better explanation. All my experience speaks to the contrary. I do know one thing though, a loose bag is colder than a snug one, the lower part can be quite narrow, on the upper part you need some room to move your arms.

TLM
 
The way that I see it, your body is going to lose heat to warming the material around it. To use the glove analogy, each digit has to warm its own finger of material, in effect creating several smaller warm pockets rather than one big one. If you are clothed and under cover your limbs are all responsible for keeping themsleves warm, if you wear less they can share the heat that they are going to lose to the imediat surroundings ie. the inside of the bag. It isn't that you lose more heat, it is what you do with the heat you are going to lose.

I think. That is how it felt when I froze while wearing polar fleece long johns under a big duvet. That bed just never warmed up.
 
Hmm.. I still think that what counts is the amount of heat you lose, in warmer surroundings you lose less heat but if you are warming up your surrounding you have lost it. If you have clothes on you when going in they are already warm or should be at least on inside, the outside will warm up beacause of the increased insulation of the bag. That's still a transient, it's the steady state that counts most.

TLM
 
It's like C said - you are going to have heat loss regardless, so the point is to use it in the wisest manner. In a sleeping bag you are relying mostly on thermal heat rather than radiant, so you need air movement to carry heat from body part to body part. Encase one arm in a shirt sleeve and it will warm the air inside that sleeve, but little else. So you might go to bed with a warm sleeve, and you might wake up with a warm sleeve, but in the meantime that arm has not been allowed to share the benefit of its heat with the rest of your body.

Add to this example the idea of being totally dressed within your bag. The heat release from your arm will have to escape from the fabric of the sleeve, move throughout the interior space in the bag, then permeate back through another sleeve, or pant leg, or whatever, before the rest of your body can use the shared heat. By then it's just as likely to have escaped from your bag as it is to have re-entered your clothing layers.

If you want to retain the insulative value of your clothes while sleeping they are better put to use underneath you to insulate you from the ground, laid over your sleeping bag to protect you from thermal loss, or stuffed along the zipper line to stop the cold drafts from slipping in.
 
I like to put on something relatively clean to sleep in, because after a week it can start to smell like a bear den. I agree that less is more except that because I hate being mummified, I use semi rectangular bags and in very cold weather I like socks of one kind or another. If it's really cold, a hat or cap is the surest way to keep you warm, unless you use a hood. I prefer not to use a hood if I can help it. But I have felt so cold that i put on some poly layers, and it does work - for me.
A liner is a must, in my experience. Silk is great, but not very tough. Poly is great, and in extreme conditions the right vapour barrier can really up the rating and control the most critical problem, which is moisture condensation. Many old timers, and some of us younger folk, use more than one bag according to the temperature.

But sometimes you get so damned tired and so much dread dressing again in the morning that you take off as little as you can get away with.
 
You must log in or register to reply here.
Back
Top