Natural Hazards

How to Survive the Cold

How long before frostbite sets in? How does cold weather change your survival priorities? You asked, the Den Mother answered.

How long can my fingers be numb before I do permanent damage? And what’s the best way to warm them up?

–Irving Jilder, via email

If your fingers are numb, the clock’s already ticking on tissue damage, but nobody knows how fast. Frankly, it depends on too many factors (ambient temp, wind, moisture, etc.). Loss of sensation, ruddy skin, or a prickling feeling mean you’ve got a touch of reversible frostnip. But just because it’s reversible doesn’t mean it’s not urgent. If you wait until your skin looks white, waxy, or mottled, then you’ve waited too long. Frostbite is setting in along with the risk of losing those fingers or toes when the tissue goes necrotic.

At the first tinge of numbness, tuck your affected parts into your body’s warmest places, like your armpits or groin, where warm, arterial blood flows close to the surface of your skin. (If it’s your feet, ask a friend.) Better yet, dip them in warm water. Warm, not hot. You may have ice crystals in your muscle tissue and sudden heat—or rubbing or brisk toweling—can tear the damaged tissue.

Remember, your fingers are coming back from the dead and they’re damn delicate. Be gentle and go slow.

In winter, do the priorities of survival change?
–Mike Berry, via email

If you’re caught in a bad way in the warmer months, the priorities of survival are typically (in order of importance): shelter, warmth, water, and food. Though you certainly need more calories to keep your body fueled in winter, your priorities don’t change—the amount of heat you generate from digestion isn’t enough to combat a hostile, cold environment. So shut out your hunger and dig a snow cave or craft a bush shelter. Getting out of the weather is critical since wind blows away body heat like no one’s business. If you can make a fire, by all means do that next, and use it to melt snow for water. Don’t munch snow—it’ll lower your body temp, and in a winter survival situation, you have to fight for every single degree.