Pro Tips: Staying Warm in a Sleeping Bag
1. At the end of each hiking day, wash the dried sweat from your body; it can act like a heat conductor, chilling you.
2. Wear a hat, socks, and extra layers on your body, but avoid putting on so many layers that you isolate your core, which is your body’s furnace, from your extremities, which get cold more easily. It’s often more effective to wear just one or two layers on your body and line your bag with other extra clothing as added insulation for your entire body.
3. Change into dry clothing to sleep, as opposed to the clothes you sweated in while hiking; damp clothes promote conductive heat loss from the body.
4. Stick a water bottle filled with hot water in the foot of your bag. In really cold conditions, put a second bottle filled with hot water in the middle of your bag.
5. Use a pad or air mattress insulated for the lowest temperatures you expect to encounter, and a second pad if you’re sleeping atop frozen ground or snow.
6. If you’re using a short pad (to save weight in milder temperatures), lay your empty pack beneath your feet to insulate them from the ground, which can drain heat from your body even in summer.
7. Pile extra clothing under the foot end of your bag to give your feet more insulation against the cold ground.
8. Use a sleeping bag liner, which can add the equivalent of several degrees of rating to a bag.
9. Eat a snack high in fat right before bed, like a candy bar, to fuel your body through the night.
See also my Pro Tips article “How to Choose a Sleeping Bag.” For reviews of my favorite sleeping bags, type the words “sleeping bags” into the Search box at left.