Tips for Staying Warm in a Sleeping Bag

Compiled by Ohio Patriot based on tips from
http://boards.straightdope.com/sdmb/showthread.php?t=445784
and
http://www.buzzle.com/editorials/8-31-2005-75832.asp


1. Use a bag appropriate for the weather. A bag with too little insulation will obviously make you cold and uncomfortable. But a bag with too much insulation will make you sweat, which will eventually make you cold and uncomfortable. Having said that, use a sleeping bag that is rated approximately 10 degrees colder than the ambient temperature. You can always ventilate a warm bag by unzipping it a little.

2. Wear clothes when sleeping. Unless you are profusely sweating, you should wear clothes while in the bag. The urban legend about being warmer without clothes is just that, an urban legend.

3. Wear the right types of clothing. Pay attention to the materials. Cotton is the absolute worst, as it has a tendency to absorb and store moisture. Wool, polypro, down, and modern "wicking" materials are much better than pure cotton.

4. Be as dry as possible. The trick to staying warm in a bag is to be dry. This means the clothes you're wearing while you're sleeping should be dry. Even the sweat absorbed by your clothes throughout the day can make you feel cold in a sleeping bag, so changing clothes just before getting into the bag should be done if possible.

5. Change socks before getting into bag. See #4. If your feet are cold, you will be cold. The socks you have been wearing all day are probably damp due to sweat. You do not want to sleep in these socks if you can help it. To fix this problem, carry an extra set of socks with you. Put on the dry pair before getting into the bag. Allow the damp pair to dry while you're sleeping.

6. Wear a knit wool hat. If you don't have a hat, wrap a towel around your head.

7. If possible, change the layer of clothing touching your skin before sleeping. See #4. Like socks, you should try to carry an extra shirt with you, too.

8. Exhale to the outside air, not into the bag. This will help reduce the amount of moisture absorbed by your clothing and the bag. (Under certain circumstances you can exhale into your bag, such as a very dry climate or if it's your last night out. But under normal circumstances you want to exhale to the outside air.)

9. Insert an insulating layer between the ground and your sleeping bag. The bag's insulation under your body gets compressed by your weight, thereby decreasing the R-rating in this area. To make up for this, you need to insert an extra insulating layer between the ground and your sleeping bag. A foam sleeping pad is ideal for this. Dry grass, leaves, or pine needles can be used in lieu of a sleeping pad. For very cold weather, consider using two layers (e.g. sleeping pad and dry grass).

10. Insert a moisture barrier between the ground and your sleeping bag. The ground gives off moisture. Inserting a moisture barrier between the ground and your bag will keep your bag cleaner and help reduce the amount of moisture it's absorbing.

11. Do not sweat when you're in the bag. If you sweat while in the sleeping bag, lots of bad things will eventually happen: your clothes will become damp, you will feel colder, and the bag will absorb extra moisture. If you notice yourself sweating, it is imperative to fix the problem ASAP. Start by partially opening the bag to let the moisture escape. If this doesn't work, try shedding some clothing.

12. After you sleep, dry out the sleeping bag. Most people simply roll up the sleeping bag after the get out of the bag. This is a mistake. During the night your sleeping bag will absorb moisture produced by your body. If at all possible (and if it's not raining), completely unzip your bag and allow the inside surface to air out for at least 1 hour before rolling up.

13. Consider using an internal bag liner. It will provide an extra layer of insulation and help keep the bag cleaner. It will also absorb some of the moisture the bag would have otherwise absorbed. (The liner is easier to dry than the bag.)

14. Use an active heat source. In very cold weather, one old trick is to take a metal canteen or Nalgene bottle, fill it with hot water, and wrap it in a fleece cover or large sock. Another old trick is to make a warm rock bed by creating a large fire over a bed of rocks, letting it burn down, carefully dig out all of the embers, then cover it over with a 3-4" layer of dirt. The warmth radiating out of the rocks will keep the ground and anything above it warm in the middle of a snowstorm. In an emergency it's a good way to stay toasty with minimal covers.

15. Try to avoid sweating during the day. The drier you and your clothes are during the day, the drier you'll probably be at night.

Good tips.
I would also add:
-Wind protection. Wind over the bag will wick away body heat. Anywind barrier will save you lots of body heat.
-Wear all your extra clothes or lay extra clothes and gear over your bag.
-In extreme weather, pile pine needles, leaves or pine boughs over your bag for added insulation.
-Pile your gear close around you to keep you from sliding off your insulated pad while you sleep.
-Wear a warm stocking cap while sleeping.

OUTSTANDING post!!

Put a hot 23 year old chick in there with you and you will stay warm!

Beat me to it.
I LIKE the way you think.

But if you get too hot you might need a firefighter