Surviving the Cold Mountain

I've asked Stanford's esteemed Outdoors Medicine specialist, Dr. Paul Auerbach, to share some of his expertise as our guest blogger.

This winter season has witnessed more than its share of lost persons, be they climbers, trekkers, or even road travelers. The obvious danger of becoming lost in a cold environment is development of hypothermia, or significant lower body temperature. Prevention of hypothermia is therefore of paramount importance to anyone who ventures into a cold environment, or who may become lost or stranded in a harsh winter environment. The precautions you take, including the equipment and clothing you carry, depend on the situation into which you enter. Here are some tips for preventing hypothermia in the outdoors:

1. Carry adequate food and thermal wear, such as Thermax, Capilene, and/or polypropylene (“polypro”) or wool undergarments. Anticipate the worst possible weather conditions. Dress in layers so that you can adjust clothing for overcooling, overheating, perspiration, and external moisture. Use a foundation layer to wick moisture from the body to outer layers. The first layer (such as CoolMax) should keep the skin cool and dry (to avoid perspiration). Add an insulation layer to provide incremental warmth. For shirts, use wool, fleece, Capilene, or polypropylene. Consider a turtleneck or neck gaiter. For pants, wear wool or pile, with a fly. Carry windproof and waterproof outer garments, mittens or gloves (with glove liners), socks, and a hat. In very cold weather, up to 70% of generated heat may be lost by radiation from the uncovered head. Boots should be large enough to accommodate a pair of polypropylene socks (“liner socks”) plus at least one pair of heavy wool socks without cramping the toes. If you are traveling in a vehicle into a situation where you may become stranded, be certain to carry a bag with extra clothing sufficient to keep you warm.

2. Stay dry. Avoid sweating.

3. Keep hands and feet dry. This is important to avoid frostbite as well. Hand Sense is a cream that can be applied to the hands to keep them dry by reducing perspiration. It was designed as a topical protectant, and is not a moisturizer. For the feet, aluminum chlorohydrate–containing antiperspirant sprayed onto the skin can help to control sweating. You may do this three times a week for the first week of winter, then once a week after that. Avoid leather boots that become soaked with moisture and do not dry out easily.

4. Do not exhaust yourself in cold weather. Do not sit down in the snow or on the ice without insulation beneath you.

5. Seek shelter in times of extreme cold and high winds. Don’t sit on cold rocks or metal. Insulate yourself from the ground with a pad, backpack, log, or tree limb. Carry a properly rated (for the cold) sleeping bag stuffed with Hollofil II, Quallofil, or down. Insulate hands and feet well, even when you are in your sleeping bag, which should be fluffed up prior to entry. Do not enter a sleeping bag if you are wet without drying off first if possible.

6. Do not become dehydrated. In the cold, dehydration is caused by evaporation from the respiratory tree, increased urination, and inadequate fluid intake. Drink at least 3 to 4 quarts (liters) of fluid daily. During extreme exercise, drink at least 5 to 6 quarts per day. Ingesting snow is an inefficient way to replace water, because it worsens hypothermia. Drink cold water from a stream in preference to eating snow. Do not skip meals. Do not consume alcoholic beverages in cold weather. They cause an initial sensation of warmth because of dilation of superficial skin blood vessels, but this same effect contributes markedly to heat loss. At night, fill a canteen or Nalgene water container with at least 1 quart (liter) of water, and sleep with it to keep it from freezing.

7. Consume adequate calories.

Paul S. Auerbach, M.D.
Clinical Professor of Surgery, Division of Emergency Medicine
Stanford University School of Medicine
Editor, Wilderness Medicine
Blog at Healthline, Medicine for the Outdoors