Make Your Sleeping Bag Warmer

8 easy ways to fortify your sleeping bag

Louise Albershardt knows cold. That's because the 48-year-old Montana resident frequently unrolls her sleeping bag atop 10,000-foot-thick slabs of ice. A professional ice-core driller and veteran of expeditions to Antarctica and Greenland, Albershardt has bedded down in temperatures as low as minus 58°F. In such conditions, she's learned that nighttime comfort requires more than a plush bag and a thick pad. When she works with the U.S.-Norwegian Scientific Traverse team in East Antarctica this winter, she'll depend on the following techniques to stay warm.

Add spice "Jazz up meals with curry and chilli powder to boost blood circulation and body temperature," says Albershardt. Plus, eat plenty of high-calorie foods to give your body extra fuel to stay warm.

Wipe down Bathe before sleeping. Dirt and sweat can clog your pores and reduce skin respiration, making your body feel clammy.

Drink up One hour before bed, she warms up with this fiery brew: 1/8 to 1/4 teaspoon of cayenne pepper mixed with 8 ounces of hot chocolate, lemonade, or honey water.

Insert liner To reduce the air space her body needs to heat up, Albershardt slips a silk liner into her sleeping bag. Silk is half the weight of most synthetics; try mummy liners from Sea to Summit ($55; seatosummit.com) or Design Salt ($50; designsalt.com).

Hit the bottle Stash a Lexan bottle filled with hot water in your sleeping bag. Place it near your belly to warm the circulating blood.

Strip down Change into fresh clothing before turning in, and dry your wet garments overnight alongside your body in the bag.