Degrees of Comfort

Buy the Warmth You Need

Pegging temperature ratings may be an inexact science, but a few general guidelines apply when shopping for a sleep sack.

Set your temperature limit. Figure out what's the absolute minimum temperature at which you'll likely use the bag. Take into account cooler temperatures at night at higher altitudes and latitudes.

Err on the warm side. When did you last hear someone complain about being too warm at night? Can't decide between a 20-degree or a 25-degree bag? Go for the 20.

Exceed your budget. When people finally break open their wallets and buy a decent bag, it is usually after a succession of unsatisfactory purchases. Spare yourself the buyer's remorse and the uncomfortable nights, and make your first bag a quality bag.

Photo Essay: Hiking the Andes with Mountain Lodges of Peru

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1. Women, on the average, generally sleep colder than men. In the same conditions, a man might be comfortable in a 40-degree bag, while a woman might need a 30-degree bag to maintain the same level of comfort. The market has responded, with femme-specific bags now available.

2. The warmest, most efficient sleeping bag mimics the shape of your body (i.e. mummy bag). If the bag is too big, your body wastes energy heating up “dead space. Adjust the bag’s drawstrings and neck collar….on cold nights, you want to seal in warm air.  Some bags even come with hoods that let you really turtle in the body heat.

3. If conditions are dicey, make sure you use the bag properly. Get into the bag promptly, and zip it up. Never get in a sleeping bag wearing wet clothes (if necessary you can put them into the bag to help dry/warm them during the night).

4. To increase warmth/lessen pack weight, plan on utilizing your down coat, hat, fleece pants, socks, and gloves as part of your “sleep system.” These accessories keep you warmer. A hot cup of tea or cocoa before getting into your bag will help increase the energy your body has to stay warm.

5. Modern sleeping bags have sophisticated venting systems (i.e. zippers in the foot-box area.) Staying cool in a too-warm bag is easier than staying warm in a bag with insufficient insulation.

6. Consider your end use. If you are car camping, weight and compressibility aren’t as much of an issue as backpacking. If you are backpacking, bring your pack along when you are shopping.

7. Invest in a good sleeping pad; most of your body heat will escape into the ground, so find a pad that comes with some sort of insulation against the cold. A good number of new pads have integrated fabric that reflects the heat back up at you. Silk/cotton bag liners also add an extra 10 to 12 degrees of warmth (and can be used on hot nights with an unzipped bag.)