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Promethean
2008-05-28, 22:31
Hi all,

I was recently over in Patagonia during a cold snap. The main topic of conversation around the fire at night was whether or not to rug up before going in the sack. Opinions differed between those who used an inner sheet and wore thermals while sleeping (ie the more layers, the warmer you are), and those who argued that a sleeping bag works best when there is maximum skin contact with the walls of the bag, as the bag is specifically designed to trap every iota of body heat and radiate it back. Does anyone know enough about sleeping bag design to make a call about whether extra layers or fewer layers keeps you warmer?

Thanks
Joel

Mutinousdoug
2008-05-29, 00:16
Depends entirely on the design of the bag.
HTH

KLeth
2008-05-29, 03:55
Hello, our sleepingbags (Helsport) becomes a lot warmer when we put fleece liners into them. Wool underwear adds to it as well.
Never had a sleepingbag where extra insulation did not add to the heat retention.

Seeker
2008-06-15, 00:36
...and those who argued that a sleeping bag works best when there is maximum skin contact with the walls of the bag, as the bag is specifically designed to trap every iota of body heat and radiate it back.

just my opinion, but i think it's a marketing trick to get you to buy a warmer bag... heat isn't light.... it's just ''heat". and if the later argument were true, it would 'radiate back' regardless of whether you were nekkid in your bag or not... most people are sheep. your own experience will tell you you're warmer in a bag when you wear something like longjohns to bed... listen to your instincts, and i'm sure you'll come to the same conclusion.

CaSteve
2008-06-15, 02:13
I'm not sure sleeping bags radiate heat back to you, but you radiate heat. I believe the argument for sleeping wearing as little as possible is that you warm up the bag quicker & therefore more comfy. A cold bag is, well, cold.

Amigi
2008-06-15, 02:39
Seeker nailed it. It's all marketing.

dropkick
2008-06-22, 08:20
Common sense says more layers more warmth.

I always use a percale sheet liner in my bags.
I've been doing this for very many years.
My reasons are many:
-Sheets are a lot easier to clean than bags.
-You're warmer in cold weather with a sheet
-And oddly, cooler in warmer weather.
-The sheet warms up much faster than the bag.
-A bag with a sheet doesn't get clammy and bead up with moisture inside, like some bags alone will.

mattzcoz
2008-07-05, 13:35
Marketing hype - layers of material and trapped air will keep you warmer, and if you wear things in your bag that you might need to wear while not sleeping, you're saving weight also. But use a bag liner, at least to keep the inside of the bag clean longer. I use a silk one (lightweight & packable) from JagBags (http://www.jagbags.co.nz/products.htm). Layers give you flexibility in temperature control.

CaSteve
2008-07-05, 19:54
Hi all,

I was recently over in Patagonia during a cold snap. The main topic of conversation around the fire at night was whether or not to rug up before going in the sack. Opinions differed between those who used an inner sheet and wore thermals while sleeping (ie the more layers, the warmer you are), and those who argued that a sleeping bag works best when there is maximum skin contact with the walls of the bag, as the bag is specifically designed to trap every iota of body heat and radiate it back. Does anyone know enough about sleeping bag design to make a call about whether extra layers or fewer layers keeps you warmer?

Thanks
Joel

I have found that fewer layers + sharing a sleeping bag with the wife with maximum skin contact is the warmest. I'll stop there since this is a family show....

:gob_censo