trying to stay warm

[SR540Beaver]

Eagle69,

 

Sleeping on a cot is like sleeping on an air mattress. It allows cold air to circulate underneath you. If all you have is your bag for insulation, your body weight will compress the insulation and decrease its effectiveness. I attend all of the troops campouts, but I really could do without cold weather camping. I enjoy not sweating like a horse like summer camping, but sleeping on the ground while bound up in a mummy bag is torture for me and my old joints. I get little sleep on these campouts. I have used a cot in cold weather and stayed cold.....but I've stayed cold using a pad on the ground too. This past month the temps overnight were around 32 and I used a 15 degree bag inside a 20 degree bag on top of a self inflating Thermarest and "slept" very toasty for once. The bag inside a bag left little wiggle room, so my joints gave me fits and kept me awake much of the night. I think a cot can work as long as you get enough insulation under you. I think it will take more than your standard sleep pad. Perhaps a foam rubber pad of about 3 inchs on top of the cot would be enough to keep the cold from reaching you and your body would heat up enough of it thru your bag to keep you warm. I've been interested in trying this myself, but a cot and a big foam rubber pad takes up a lot of space for traveling.

[SR540Beaver]

Lisa,

 

I would assume that your boys have low temp bags since they live where the temps drop so low for multiple months. But, I've been around scouts long enough to know that new parents will skimp on price for items like sleeping bags. Many will get a rectangular bag from Wal-mart for $20 and think it will keep their little scout warm. My rule of thumb is to research equipment and buy the best I can afford. I don't care how great a piece of equiment claims to be, I just can't bring myself to pay $600 for a bag. Likewise, I won't waste blowing $20 for a piece of junk. I had my eye on a "sleep system" before Christmas. It is a Wiggy bag. Wiggy makes the bags for the Navy Seals. It is a bag inside a bag system. Individually, one bag is good to something like 30 or 35 and can be used in summer. The outter bag is good to 0 and can be used for fall and winter. Together, they are good to -40. The insulation is laminated to the bag which eliminates needle hols and helps to make the bag waterproof. It is quite an elite bag and runs around $450. I had equipment fever and really wanted this system. Heck, I'd never need aother bag again with this system. Then reason took over and I realized that my outings were never going to expose me to the environment that a Navy SEAL would be in. I'm going to be in a tent and totally waterproof bag just isn't that important to me. I have a 15 degree Sierra Designs mummy bag. I decided to buy a $40 Bass Pro Shop 20 degree mummy bag that I can slide my 15 degree bag into. I got the same effect as the $450 bag for $40. I say all of that to say that you can probably stick a decent bag inside another decent bag for a lot less than buying one super duper bag that costs a fortune. That way a boy can custom fit his needs. If he brings a -30 bag and the temps end up being 30, he'll burn up all night. If he has two bags, he can use one or both depending on the needs.

 

We had a former SM who would not allow the scouts to use the warmers in sleeping bags. He felt that they got too hot and could burn exposed skin. My personal take is that they do not get that hot. I'd allow them to use them in their bags, but would want them to slide them into the bottom of a sock first just to be on the safe side.

[SR540Beaver]

Just to clarify, I didn't mean sliding a warmer into a sock they are wearing. I meant to use spare socks as a cover for the warmers to avoid possible burns.

[ScoutNut]

I have used cots in cold weather, when camping with the family in larger tents. I had no problem with staying warm, but that is mainly due to using the air space under the cot for storage. I have aluminum Coleman cots so there are no cris-crossing legs. I stuff my clothes bag, coat, shoes, dirty clothes bag, etc, all under the cot. It saves room in the tent & insulates under the cot. A win-win all around! Of course the darn thing takes up a bit of space so it is for car camping only & does not fit in smaller tents.

 

[FScouter]

Eating right before bed is not a good idea. Digestion requires a big supply of blood. The body diverts blood from the extremities to the digestive tract. Reduced blood in the extremities makes you feel cold.

[SR540Beaver]

Let me clarify my statement about eating cobbler right before bed. It was usually an hour to an hour and half before lights out.

[CalicoPenn]

GWD-Scouter - by all means, feel free to use anything I typed if you find it useful. I was an Okpik Instructor at Maine National High Adventure Base back in the mid-80's (and majored in Outdoor Recreation/Environmental Education in college) - everything I know about cold weather camping comes from either the scouts or from college courses (which were all practical, hands on, experiential education courses - taught and learned in the field).

 

I need to make a bit of a correction about the information I shared about the pads. The Thermarest Z-rest is a closed cell pad - there is nowhere to blow in any additional air. The Thermarest classic (aka standard) is an open cell pad, with a valve that allows extra air to be blown into the pad - its a "high-tech" air mattress essentially, just with thousands of small, open cells, versus a couple dozen at the most large, open cells of a traditional air mattress.

 

For anyone wondering what the difference between the two pads are, a closed cell pad (say an ensolite pad or a Z-rest) has thousands of tiny, fully formed and sealed "bubbles" packed and compressed together with no air transfer between the bubbles. When you roll up a closed cell pad, it takes up the same amount of space as when laid flat (just in a different form spatially so its not obvious to most people). An open cell pad is composed of a couple dozen (typical air mattress) to thousands (think Thermarest classic or foam rubber) of mostly formed "bubbles" that are not fully sealed against one another (like an O with a small part taken out of the side) which allows air transfer between the bubbles. When these are rolled up, the air within the pad is expelled and the pad takes up less space. One of the early selling points of the Thermarest classics was that you strolled into camp after your long hike, opened up the valve of the pad and left it on the ground while you set up your tent and the rest of your camp and when you got back to your pad it was "fully" inflated. That still works, for the first few times but eventually, especially if, like me, you always blow extra air into it to firm it up, it no londer works very well.

 

I've never found it neccessary to carry two pads with me, not even when camping at below zero temps (though an additional blanket under the pad was always nice then) but if I had to, I would carry a closed cell pad to put under a Thermarest open cell pad. A thinner piece of ensolite would work just as well and serve as additional insulation.

 

Kind of as an aside - when I was teaching winter camping to Scouts up in Maine, staff were outfitted with the same equipment as the units we were leading - that meant that if a unit didn't bring their own Thermarests with them, we didn't get to bring ours out in the field either - it was a rare occurence to be able to head out into the field with our Thermarest strapped to our backpacks and when we got to, we were the envy of the rest of the staff.

 

CalicoPenn

 

 

[CalicoPenn]

A couple responses - felt my pad correction was getting a bit too long.

 

++ In my experience, less really is more - for the reasons I stated. I know that it is counterintuitive, but the more clothes one wears to bed, the colder one will get. Initially, when you first get to bed, it will be a bit chilly, maybe even downright cold, but you will warm up as your body heat warms up the bag. The problem with wearing multiple layers in bed at night is that you aren't awake when its time to strip off a layer. When wearing multiple layers during the day, as you become more active and start generating more heat and sweat, you remove layers to regulate the heat and if you don't begin removing some layers, you'll end up getting colder and colder as the day wears on. At night, when you overheat, you'll start to sweat and if you start taking off layers (asuming you wake up), your sweat will evaporate rapidly causing you to cool down - fast - and then begin shivering, then thinking your cold, you'll put on more clothes, and starting the process over again. If overheating doesn't wake you up, then you're much more likely to wake up cold (and probably early too - when you really start to feel cold).

 

Starting off in your sleeping bag in one layer, letting your body heat warm up the bag, then letting the bags inuslation regulate your heat allows for the majority of people a much better nights sleep. Its the same principle as sleeping in your bed at night, you get in and the bed is cool, then it warms up, you fall asleep, and by morning your snug as a bug in a rug and don't want to leave your nice, toasty warm bed - and I'd be willing to bet you aren't dressed in multiple layers.

 

When I taught winter camping, I recall only one night when I wasn't woken up at 1 or 2 in the morning by kids (and/or adults) that got cold - and that night I was leading an Explorer Post of older lads who actually listened to us and took what we told them seriously.

 

++ I like the idea of a hot water bottle in the bag with you - just make sure its a wide-mouth Nalgene bottle with a well set cap (and not fancy spouts). The water will help with the initial warming of the bag and keeping the water in the bag with you means you have fresh, unfrozen, and at least lukewarm water to drink in the morning (always drink lukewarm or warmer water while camping in the winter - cold water cools your core down pretty darn fast, lukewarm water is usually at least similar to your body temperature and won't cool you down).

 

++ For before bed snacks (and FScouter is spot on with this - right before bed is a bad idea - though an hour before bed is ok - digestion has well progressed by bedtime) I loved fig newtons (and strangly, I only like fig newtons in the winter while camping or cross-country skiing) or oatmeal.

 

++ Yes, the ground is generally a giant heat sink, however, the interesting thing about the ground as a heat sink is that it isn't a quick sink like an air mattress would be - its a slow process - it takes a while for the subsurface to get get cold or freeze up and it takes a long time for the subsurface to warm up - Thats why pads work well to insulate you from the ground, the ground just won't take up all that much heat from your pad - it not an efficient heat sink at all. Also, and again rather counterintuitivly, snow and ice are fairly decent insulators themselves.

 

++ LisaBob - for your temperature ranges, a fleece sleeping bag liner will work wonders - they're available at most outdoor stores now, but are also easy to make - fleece is available at most fabric shops and if you don't have a fabric shop around, K-mart, Walgreens, Target, and similar stores, sell cheap fleece blankets that can be sewn together to make a bag liner. These liners can serve as a warm weather bag (warm with cool nights - spring and fall - not summer) all on their own. Otherwise, same things apply - don't over layer, etc. - the lads bodies will generate the amount of heat needed to keep them warm in a sleeping bag. They could also stuff their bag with some of the clothes they plan to wear the next morning - the clothes will be warm when they put them on and will act as additional insulation at night.

 

CalicoPenn

 

[Lisabob]

You guys are a gold mine of information. I shared several of these posts with my 11 yo, who is getting ready for a late January camp. Hopefully he'll actually remember to do a few more of these things and share the info with his patrol mates too.

 

All the tips here would've been so helpful to us last year - when he crossed over from webelos and went camping less than a week later, in single digit temps, with practically no training and inadequate gear (what we know now...). Of course he had a lousy time, froze the whole weekend, and swore he'd never camp in snow again. Happily, he's giving it another try this year. I think I'm going to spin a thread into the cub scout section to suggest a little more webelos II training/coordination with troops prior to cross-over.

 

Lisa'bob

 

 

[SR540Beaver]

Calico gave a lot of good info on sleeping pads. I am the pround owner of a Thermarest self inflating pad. Many people don't read the instructions and will store their pad compressed and rolled. Don't do this. It compresses the insulation and eventually it will not expand as it should and provide insulation. Same with a sleeping bag. Never store them compressed. The only time my sleeping pad and bag are rolled is the hour or two going to and returning home from camp. Once I get home, the bag is hung up in a closet and the pad is stored unrolled under the bed with the valve open. This will extend the insulating properties of both items.

[Lynda J]

I sleep on a cot because of an old hip injury. I went to the fabric store and got the quilted material that you line drapes with to insulate them. I contact sprayed it to the cot, works great for keeping cold air from transfering up under me. I then put a fleece liner inside my bag. And I do wear socks, but I wear socks at home too. But leave them in the bag until I get in.

I have camped to 22 and not been cold. But it does take about 10 minutes to warm up the bag once you are in it. And to be honest my bag is not an expensive one. It is rated to 25. I have always been told to take the temp rating of the bag and add 10 to it and that is what it will really be warm to.

 

 

[Eagle74]

I'm one of the cot users, too. Use it year-round. Mine is a little different than those described above, though. It is a Byer Allagash cot; sits only about 6 inches above the ground and folds up as small as a typical collapsible outdoor chair.

 

In winter I use it with a 3/4" closed cell foam pad on it, "0-degree" bag, wear fresh polypro long underwear and dry socks with a thin fleece sweatshirt and stocking cap. To fill the airspace under the cot (like ScoutNut) I stuff my coat and clothes worn that day under part of it and my clothes for the next day under the rest. Toasty all night unless nature inevitably calls - why does this only happen during the coldest of nights?

[dan]

bizzybb

My first campout with the troop a few years ago I only had a 30 degree bad and a really cheap 50 degree bag, I but them together and had a very warm night. It got down to 15 degree that night, so I say go head and use both bags.

 

I thought I heard everything on how to stay warm at night, I learned a few thing from this thread.

I do have question though, it was stated to keep the sleeping bag stored until ready to use because of moisture. What if you have a 2 night campout, like we have this weekend, what do you do with your bag during the day after sleeping in it all night? I take mine out for a while and open it up and let it air out, this sounds like it goes against what is being said here, keep it stored until use because of moisture.

 

[Eagle74]

Good discussion with good info all around. Did however want to clear up the air regarding air mattresses; there is an impression left that it's the air itself in the air mattress that results in poor insulative properties and that's not the case. Air is a good insulator and it's what you want in your sleeping bag, your clothing, etc. - just not wide open air space.

 

Basics (not intended to insult anyone's intelligence here) - Heat transfer occurs by conduction, convection, and radiation. Let's apply these to the air mattress.

 

The air mattress is a good insulator in relation to conduction. Air is a poor conductor of heat. Hence air space in double pane windows, air space in down-filled apparel, air space in holofill, thermarest pads, etc. to reduce the occurrence of conducted heat transfer.

 

Open air space - like that inside an air mattress - is not a good insulator in relation to convective heat transfer. The large, wide open air space in an air mattress contains nothing to prevent convective heat transfer - there is constant circulation (air current) in the wide open air space of an air mattress. Down, holofill, the filler in a Thermarest mattress, etc. create small air pockets which do not allow convective currents throughout the space between the outer and inner shell.

 

Open air space is not a good insulator in relation to radiated heat transfer (unless the goal is to allow heat to radiate away for cooling purposes). Air allows the free travel of radiated heat away from the warmer object - think of that warm feeling sitting by the campfire. The open air space in an air mattress allows radiated heat to travel freely from your body/sleeping bag to the ground three or four inches away. Down, holofill, or other solids stop heat radiation directly to the ground, instead absorbing the radiated heat and releasing it primarily as conducted heat across the solid material. In a sleeping pad for instance, that means that the radiant heat transfer away from the body is stopped close to the body. Result is a slower progression of less heated space the further away from the heat source you get.

 

In basic terms, that's why a regular air mattress doesn't work so well, but a Thermarest-type "air mattress" does. It's also why if one uses a cot in cold weather it's essential to use a pad on the cot and fill the large open air void under the cot.

[bizzybbb]

Thank you so much to everyone who replied. Much great information. Calico, I agree with everyone that your information was so comprehensive and right on target. I, too, would like to use your text to give to others in my Pack.

It sounds like I am doing most everything right. Didn't of course think about completely changing, down to my underwear, before getting in the bag. I'll try that next time. Make the son do it too. I also realize that I probably should try layers with only synthetic, and though I love the thickness of those old Hanes thermals, being cotton, they're probably not the best solution. Didn't see anyone mention anything like UnderArmor. I have these for my fitness wear, and was wondering if they would make a good base layer next to my skin because of the compression factor. Also, nobody mentioned putting my bag inside another bag. Is this a good idea? I will need to purchase spring weight bags anyway, and thought I could maybe put my 15 degree inside a 40 degree. I know all you northerners are thinking "how cold can it get in North Florida?" but believe me, I've been colder here on a 30 degree night than in Colorado on a 10 degree day. Many people say it comes from the humidity. Damp chill that goes right to the bone. And, OK, OK, I guess I'll ditch the fat air mattress on those cold campouts.