JWR:
As a long time camper, backpacker, outdoorsman, and now K-9 SAR Tech, I understand that temperature regulation at night can be a problem. Here are some of the tricks I’ve used:
I almost always use a silk bag liner. This has multiple advantages: 1) silk feels warm when it’s cold and cool when it’s hot (2) silk protects the sleeping bag from dirt, minimizing the amount of needed washings and prolonging its life (3) in the winter, silk will make you bag about 5-10 degrees warmer (technically speaking, this “drops” you temp rating number- a 35 degree bag becomes a 25-30 degree bag). All 3 are mummy bags.
I have multiple sleeping system, 3 primary bags, and I choose depending on the weather. I use a 40 degree bag (Mountain Hardware) from the latter part of Spring through the beginning of Fall, a Sierra Designs 30 degree bag for the transition into and out of Winter. Both of these bags are synthetic. During the coldest trips I use a Western Mountaineering 850 fill down sleeping bag rated at 5 degrees (with a liner this is -5). You can’t beat down for those really cold nights.
During warm months, stay hydrated. This is a major tool for body temperature regulation. Before sleep I’ll drink a good amount of water, and this is also the time I bathe. This will lower my body’s temp. It’s like a cool shower before bed. One great trick is to wet a bandana, ring it out, and put it on the back of your neck. Make sure you’ve got adequate ventilation in your tent. If you haven’t used the guy lines this could be one of the problems, as the rain tarp begins to lay against the tent wall, increasing condensation because of the reduction of air flow. Choosing a quality campsite also greatly influences air flow. If you can camp near water you’re normally going to have some movement of air.
During the cold months I, as JWR already mentioned, always sleep with a knit cap on. To keep my feet warm, I heat water and put it into a Nalgene bottle, put the bottle into a sock, and stick the sucker down into the bottom of the bag. Warm goodness all night long. I also eat a fatty, sugary snack before bed (a candy bar or something similar). This gives my body fuel for the night, and I keep a snack handy in case I wake up. I will also drink warm liquids. My favorite is hot chocolate with a hunk of butter in it. The butter provides extra, longer lasting fuel for my body’s furnace.
Campsites in the winter should also be chosen based on temp. No longer will I camp in valleys and on peaks, I like a place about halfway up the hill. This seems to minimize exposure and the settling of cold air around me.
Last point- I always sleep naked, with the exception of a big, fluffy pair of sock I only use for sleeping. They don’t go on until I’m getting in the bag, and the same socks are used for the duration of the trip- one night to 30, and that’s okay, because they never get dirty; they’re only slept in. Nakedness limits the layers between me and the bag, allowing the bag to more efficiently do its job of trapping air and using it as insulation. In the AM, before I get out of the bag, I pull all my clothes into the bag with me for about 15 minutes to warm them up, so I don’t lose heat to the cold cloth. Pull the clothes in a layer at a time so you don’t freeze yourself out (i.e. base layers for about 10 minutes, put ’em on, insulation layer about 10 minutes, put it on, outer layer 5-10 minutes, put it on)
Hope this helps, and sleep well! – D.B.
Hi Jim,
I can really relate to Nikki S.’s dilemma with sleeping bags. In my younger days (mid 1980s) I lived outdoors for 2 years in a wilderness setting in a northern climate. This was before manufacturers figured out men and women are built differently. I was constantly dealing with an ill-fitting backpack and sleeping bags built for men. One of my few claims-to-pseudo fame is that I worked with some of the major manufacturers in the 80’s to design outdoor equipment for women. My 5 ft. 6 frame was used as a template for some of the first sleeping bags and backpacks. I did a lot of field testing of outdoor product for the manufacturers and was proud to be a part of the evolution in gear for women.
In the early days, when I had no choice, I would sleep in my polypropylene, wool socks and watch cap. Even then I was still cold and would have to stuff my extra clothes into the empty voids of my too big sleeping bag. If it was really cold I would heat up some boiling water and put it in my water bottles. One would go down by my feet and I would curl up (trunk area) with the other one. If I was camping in the summer and was too warm then I would not zip the sleeping bag all the way up. I used it more as a comforter on top of me with my feet tucked into the foot box. If a body part got too hot then you could easily slide it out from underneath the “comforter” sleeping bag to cool off.
These days, manufacturers make product in sizes and gender. Look for one closer to your size, i.e., height, width at shoulders and hips. In cold weather I still will wear a hat and start out with Thorlo socks on when I go to bed. If you are still cold then add hot water bottles, or an extra layer such as a liner bag. In warm weather I still don’t zip my sleeping bag up and just use it as a comforter so I can easily regulate my temperature needs.
Which type of sleeping bag to buy? Here is where I run contrary to what most readers of this blog would recommend. I worked for 10 years as an outdoor survival professional and interacted with countless other people in the profession. 98% of staff would only use goose down sleeping bags. However, we issued synthetic bags to the students. The only exception would be if we were working a river course such as rafting or kayaking. Then about 50% of the staff would go with the synthetic bag. Synthetic bags are heavier and bulkier so if space is a consideration then this is not necessarily a good choice. If you are car camping or not in a backpacking type situation then go with whatever works for you because size and bulk won’t matter.
If you are in a backpacking type situation where you are going to have to carry everything that is going with you, then I recommend goose down. If you are using goose down, then the trick is that you have to actually care about your gear, have a little outdoor experience and be aware of your surroundings. (Thus, the reason we put students in synthetic bags). To help eliminate the fear of your goose down bag getting wet there are a few things you can do. I use a heavy gauge trash compactor bag to line my sleeping bag compression sack. They are very waterproof and do not tear easily. You could also use a small waterproof river dunnage bag instead of a normal sack if you are really worried about it.
I also pay a lot of attention to where I set up my sleeping area because I don’t use tents. I either sleep out under the stars or may set up a 6 X 8 polyester rip-stop tarp. I don’t set up too close to the fire or in an area where if it rains hard you are going to have a torrent of water running through your sleeping area. If you are sill worried about your bag getting wet then you can put the bottom half of your bag in the trash compactor bag, throw a quality tarp over you or use a gore-tex bivy bag.
In all my years of living and working in an outdoor wilderness setting I have never had the wet sleeping bag syndrome. But then, I consider my sleeping bag as one of the most critical pieces of survival equipment and pay attention to its care and placement. I’ve crossed a hundred plus river and streams while carrying a backpack and yes, I have taken a couple of falls. As a result, my backpack did get soaked on the outside but all my stuff on the inside was dry because I use trash compactor bags to line the main compartments and sleeping bag. They are worth their weight in gold!
Take care and keep your powder and socks dry. – Skylar
Sir:
I do better with a bag for women, my favorite is The North Face brand Cat’s Meow for women. I add a silk liner if I need extra warmth. God bless, – Patti G
James:
To the lady asking about sleeping bags: I rediscovered for myself a few years ago on a snow camping trip with my Boy Scouts the comfort of a hot water bottle. Since we are in Southern California so it is rare for us to camp in freezing temps and while we did rent extra warm bags for this trip, the first night was a chiller. The top of Mt. Pinos hit 12 degree F. and to a bunch from the beach it was not pleasant. While cuddling a hot chocolate the next morning it hit me that the easiest way to stay warn, with what we had, was to fill our Nalgene liter water bottles with near-boiling water, put one in a sock, and stuff it in the foot of the sleeping bag. I was amazed at how well this simple trick worked! The old folks from pre-electricity had something good going. Toasty warm feet all night, and the water was still hot enough for hot chocolate in the morning. Easily done if you have some way to heat water.
I would imagine that the same trick, with a few bottles of cold water, would work just as well in the summer heat. Wrap them in something to slow and absorb the condensation and snuggle. – JR
Mr. Rawles,
My experience as a reservist in the Canadian Army gave me a little bit of incite about sleeping bags, especially in extreme cold. When I was serving, the Canadian Forces sleeping bag system was comprised of a valise carrier, a Goretex Bivy bag, a down-filled outer shell, a down filled inner, a cotton liner and a goofy “hood” with straps for the wearer to slip his/her arms through to keep the hood in place while they slept.
An air mattress and ground sheet (a militarized tarp) were also standard issue. This system worked very well in extreme cold and warm temperatures. I slept comfortably outside a shelter as low as -20C (-4F), inside a semi-heated tent down to -40C (-40F), and in summer months as warm as +20C (68F) by layering up and down as appropriate.
The biggest downside of this system though was being down, one had to be very careful to air out and dry the outer shells in the event they got wet. Of course, also being nylon, one had to be extremely careful to keep the assembly away from an open fire.
Your advice about keeping your head warm is well worth noting, but a critical lesson I can speak to first hand is to not put your head inside your sleeping bag with the rest of your body as you sleep. In cold conditions, moisture from your breath will cause additional condensation to form inside your sleeping bag which will make you colder.
I will note as well that that wearing a “sleeping cap” (a toque, as we call it up here in Canada), will keep you warm, however it will also mat down your hair significantly to the point where I found I’d sometimes wake up with bad a headache. The issued “hood” alleviated this problem as it was loose, but many troops found the armpit straps very annoying. One solution I had was to simply wrap my head loosely in a large scarf or a Keffiyeh.
Another consideration as well is to not excessively layer up your personal clothing when sleeping inside a sleeping bag. My first winter exercise as an inexperienced Private, I wore long underwear and wool socks inside my sleeping bag and woke up the next morning miserable without getting a wink of sleep. During the night, I was so warm, I had sweat excessively as a result of overdressing and the sweat actually made me colder at night.
It may sound surprising, but with a good sleeping bag system, even when it’s -40C, one of the best things you can do (conditions allowing) is hop in and strip right down to your underwear. When you wake up in the morning, keeping your inner layer of clothes inside the sleeping bag off your skin also warms them up nicely.
If sleeping on the ground, pretty much regardless of the temperature, it’s critical you keep yourself off the surface. Surface temperature outside a heated shelter is almost always colder than your body temperature and lying on it, even in an insulated sleeping bag, will cause a lot of heat loss. A cot, air mattress, ground sheet, evergreen boughs, even your outer layer of clothing work well to serve this purpose. If using an inflatable air mattress it’s important not to blow it up using your own breath, as air you exhale is at body temperature, and as that air cools, it contracts.
After waking up, it’s a good practice to air out and dry your sleeping bag (if possible), not only to ensure it’s warm the next time you use it, but also for hygiene consideration. A damp, dingy sleeping bag WILL grow mold over time, so as is feasible, in addition to regularly drying it out, it is a good idea to clean a sleeping bag following manufacturer recommendations. If it is not feasible to wash the entire sleeping bag, at the very least, washing the internal, cotton liner regularly is a good idea. For non-military sleeping bags, a detachable, machine washable liner, I would say is a very desirable feature.
One closing remark on sleeping bags. The Canadian Forces issue sleeping bag was, relatively speaking, a gigantic piece of kit. It can be tempting, especially in constructing a lightweight bug out bag, to overlook such a large item, however, I have a personal experience that I think emphasizes why that may not be prudent.
In the military I once did a basic five day survival exercise course with the Canadian Rangers (the “Arctic patrol” Reserve force of the Canadian Forces) where we were paired with another soldier, given half of an Individual Meal Pack (IMP) ration (the Canadian equivalent to an MRE), issued a small kit with an axe, flint, empty coffee can, some snare wire and paracord and given orders to “survive” as if we were stranded. We were in northern Alberta, and even with a Chinook and unseasonably warm temperatures (of about -5C), the heaviest winter kit we were issued (parkas, snow pants, mukluks) with a fire and well constructed lean to, it was very difficult to stay warm. I didn’t sleep more than half an hour the entire exercise because I was so cold. (During that survival exercise, the Rangers took our sleeping bags away from us, before dropping us off.)
In comparison, I later attempted to sleep inside my issued sleeping bag following the techniques I outlined above, on pavement, unsheltered, when it was -20C with a wind-chill of -30C. I was comfortable enough that I slept like a baby that night. – L.N. in The Great White North
Howdy James,
Here’s some thoughts about choosing a sleeping bag for cold weather use. I was a scoutmaster for a rural Colorado Boy Scout Troop for 12 years, and most of our kid’s families couldn’t afford the latest synthetic -40 below bags. We found that using two sleeping bags, one inside the other, provided plenty of warmth even when camping in the High Rockies in the middle of winter. Two zero degree rated bags (summer use in our area) would be more than sufficient.
Your advice about covering the head is completely correct. We advised our kids to bring along a big fluffy bath towel for this purpose. It makes a very good thermal air dam at the top of your bag. You should always sleep wearing a stocking cap of course.
I had a friend who worked year round as a welder in the oil fields of Wyoming, and he taught me this trick; if your feet are cold, put on a hat. If they’re still cold, put on a second hat. If they’re STILL cold, put on ANOTHER hat! Eventually you’ll stop the heat loss and when your core temperature catches up, your extremities will warm up just fine. Try it, it really works! (but you do look a little goofy with 4 hats)!
Stay Warm, – Pistol Pete