Hi All, I've decided to get serious here and post a bunch of material. I am going to publish a series of E-books about camping ideas and about my experiences. So I'm going to publish several excerpts from my E-books here, and also many of my posts to certain other lightweight group.
I hope you find this enlightening, or enjoyable, or helpful.
I get to BS a bit because this is my site. I'm told that soon I will be syndicated and others will use my stories. Thats wierd.
Jim Shaw
Thursday, June 12, 2008
Cozy warm - winter warmth
This is meant to be a comprehensive but short treaties on sleeping “Cozy” [skin] warm vs. “core warm”. First the given: Mitts are warmer than gloves because the fingers are next to each other and keep each other “cozy” warm (98 degrees).You need good insulation under your sleeping bag that will not compress. A mummy bag is the warmest shape because it limits the volume to be heated, but you have to be fully inside it with the hood closed down to a breathing hole and all internal adjustments tightened and your “neck yoke” (if you have one in your bag) spread over your shoulders to keep the cooler air around your face from mingling with the warmer air deeper in your bag. A snug fitting bag is warmer than a loose fitting bag. A balaclava is warmer than a hat. Tucking each layer of underwear, fleece etc carefully into each other will make you warmer. Elastic in the design of the sleeping bag – to keep the insulation next to you and to restrict air flow Given enough insulation and a fuzzy liner you would be more “cozy” warm sleeping naked because your skin would be in touch with other 98 degree skin which is the warmest you can get. A fuzzy liner is warmer than nylon next to your skin, because of this wearing a thin fleece layer is more cozy than being naked in a nylon bag without a liner.
Other important concepts – You will eventually have to get out of this bag and if you are wearing some insulation inside your bag the shock will be less when you open your bag. If your bag is against the side of the tent and a cold wind is blowing, that side will be noticeably colder. A snow cave is warmer than a tent, but wetter and requires more energy – generating dampness.
Upper body vs. legs. In the old days down pants and bibs unzipped between the legs and then the ends would zip together so your warm legs were next to each other, this was much warmer than sleeping with each leg in down pants that are pressed together – old timers will confirm. This is for the same reason that mitts are warmer than gloves, even if you keep the fingers pressed together wearing the gloves – its not the same as all the fingers contributing to heat one space in a mitt. Still I like to sleep in my down bibs and fleece long underwear because when I do have to get out of that bag, all I have to do is pull on my huge down coat and mitts to be fully dressed.
I think the most argument is about upper body warmth. I say that if you have good bag that is reasonably snug that you should put your coat over your bag and not wear it inside. My coat is so huge that I couldn’t wear it in my bag anyway, but when I have worn a lighter down coat inside my bag my hands froze and my arms were not warm. If you slept in that same bag in the coat but pulled your arms inside so they were more in contact with your body, they would be warmer, like wise putting your coat over your bag allows your torso and arms to be in touch more like fingers in mitts and you would be more “cozy”
If a cold wind is blowing against the side of your tent, wrapping part of your coat around the side of your bag against the tent wall will add considerable insulation to that side. And finally the inside of your coat will be warmer to put on in the morning if it was against your sleeping bag all night. I wear thin gloves to sleep in even though mitts would be warmer because its easier to deal with zippers and draw strings.
I have survived an open bivouac at minus 40 and because all I had was my sleeping bag, I wore all of my clothes and snow mobile suit inside it. I was really cold. If I had put my coat over me it would have blown away or filled with snow, so I wrapped it around my feet to prevent frost bite. Fortunately there was only light snow that night and it covered my bag and helped keep me warmer, but I was not cozy warm.
Other important concepts – You will eventually have to get out of this bag and if you are wearing some insulation inside your bag the shock will be less when you open your bag. If your bag is against the side of the tent and a cold wind is blowing, that side will be noticeably colder. A snow cave is warmer than a tent, but wetter and requires more energy – generating dampness.
Upper body vs. legs. In the old days down pants and bibs unzipped between the legs and then the ends would zip together so your warm legs were next to each other, this was much warmer than sleeping with each leg in down pants that are pressed together – old timers will confirm. This is for the same reason that mitts are warmer than gloves, even if you keep the fingers pressed together wearing the gloves – its not the same as all the fingers contributing to heat one space in a mitt. Still I like to sleep in my down bibs and fleece long underwear because when I do have to get out of that bag, all I have to do is pull on my huge down coat and mitts to be fully dressed.
I think the most argument is about upper body warmth. I say that if you have good bag that is reasonably snug that you should put your coat over your bag and not wear it inside. My coat is so huge that I couldn’t wear it in my bag anyway, but when I have worn a lighter down coat inside my bag my hands froze and my arms were not warm. If you slept in that same bag in the coat but pulled your arms inside so they were more in contact with your body, they would be warmer, like wise putting your coat over your bag allows your torso and arms to be in touch more like fingers in mitts and you would be more “cozy”
If a cold wind is blowing against the side of your tent, wrapping part of your coat around the side of your bag against the tent wall will add considerable insulation to that side. And finally the inside of your coat will be warmer to put on in the morning if it was against your sleeping bag all night. I wear thin gloves to sleep in even though mitts would be warmer because its easier to deal with zippers and draw strings.
I have survived an open bivouac at minus 40 and because all I had was my sleeping bag, I wore all of my clothes and snow mobile suit inside it. I was really cold. If I had put my coat over me it would have blown away or filled with snow, so I wrapped it around my feet to prevent frost bite. Fortunately there was only light snow that night and it covered my bag and helped keep me warmer, but I was not cozy warm.
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