Originally posted by Aeteocles:
quote:
Originally posted by ensigmatic:
This is going to be one of those "pick two" things.
Here's another tidbit I recall from my very brief foray into winter camping (and I do mean very brief): Sleeping bags work best if you sleep in 'em nekkid.
I think this advice is dated. I remember reading it in my Scout handbook three decades ago.
The idea was that dirty clothes with matted down fibers is a poor insulator. Given the weight and thickness of old cotton filled field jackets and jeans, it could take a good long while for your body to warm up that extra mass inside your sleeping bag. Your bag didn't perform better, it's still a closed system, but you are wasting calories heating up an extra 10-15 lbs of clothing with you in the bag. But once warm with you in the bag, the clothes have no effect on the bag's insulation performance. Overall, you take longer to get warm, with only a little extra insulating benefit once warm.
But, these days, synthetic clothing still maintains loft in the fibers even while dirty. The trapped air in the clothing fibers adds insulation and provides warmth, even if the clothes themselves are not yet warm. Even then, some lightweight long underwear with hollow fibers or merino wool only adds like 10oz. You can get an additional 5-10 degree of warmth with high tech long underwear, with only a 10 oz penalty in additional mass you have to heat up with your body.
