Avoiding Frozen Feet —Cold Weather Footgear

William E. Davis

WITH an increase in the number or expeditions to areas of great peaks and with more and more interest in winter mountaineering, the possibility of climbers being exposed to frostbite is growing. Also the easier accessibility through improved roads and greater use of aircraft to mountains with high altitude and perennial arctic conditions adds to the danger.

Frostbite itself has been treated in Bradford Washburn’s article in the American Alpine Journal, 1962,1 so that I shall not give further details here. Any climber going to cold regions should familiarize himself with the problems and be on his guard.

The face, hands, and feet account for the greatest number of freezing cases. To the mountaineer, frozen feet are the most crippling. A frostbitten face or hand may require an expedition to return for medical aid but the victim is still able to travel under his own power. Severely frostbitten feet, if even partially thawed, demand complete immobilization of the climber if the extremities are to be saved; the victim cannot aid in his rescue by walking to help. If he should walk on thawed feet, he is nearly sure to loose tissue or even toes. The patient himself should never be consulted. He is a litter case just as much as if he had broken a leg and must not be allowed to walk, regardless of his desire to avoid being a burden on others.

Thus protection for the feet is a prime concern to climbers in regions where there is danger of frostbite. Footgear must be carefully chosen and tested. The recognition of frostbite must be known and its treatment well understood before the group departs. Adequate precautions must be taken in the field. Especially, sufficient changes of dry socks are essential and they must be used. It is difficult for uninitiated climbers to realize that in the Alaskan mountains, for instance, complete drying of boots and socks is all too often impossible as temperatures are low, and long successions of stormy, sunless days not infrequent. And alternative action, should frostbite occur, must be planned and accepted by all members of the expedition before the critical moment when the decision to turn back must be made.

Factual evidence about the prevention of frostbite on climbing trips is sparse. Information about individuals who have not gotten frozen is as important as knowledge about those who have, but the climber with frostbite always gets the attention and his friends who escape it are ignored. There is some evidence that it is not the equipment alone that makes the critical difference. There are climbers with more, or less experience. There are those who seem to be more prone than others to frostbite for physiological and psychological reasons. A limited amount of data has been gathered on expeditions to Mount McKinley. Frostbite is the most frequent injury on this peak, which is characterized by continuous arctic conditions. Some of these facts were published in the 1964 edition of Accidents in North American Mountaineering.2 William J. Mills, Jr., M.D., of Anchorage, Alaska, has specialized in frostbite for a number of years. His information has a direct bearing on the problems faced by climbers.

Conclusions based on experiences in Alaska are helpful in dealing with the problems of footgear. A regular leather climbing boot does not provide adequate protection against frostbite in cold mountains. The advantages of regular boots for normal use are well known. Leather is supple and thus, once broken in, boots are comfortable since they fit the foot. Leather is not excessively heavy yet it can be reenforced so that a boot has a hard toe to take a crampon. Leather also “breathes;” that is to say, body moisture can be dissipated through it. These properties also make a regular leather climbing boot highly dangerous where frostbite is a possibility. Once wet, it is easily frozen and anything but easily thawed. The highest incidence of frostbite on Mount McKinley in recent years has occurred to climbers wearing regular leather mountaineering boots without an outer covering or with a poor overboot. A regular leather climbing boot simply will not protect against freezing in extreme cold.

A more satisfactory arrangement is to encase the leather boot in a protective covering or overboot. Thus, an outer covering, usually waterproof or water-resistant and often wind-resistant, is slipped on over the boot. An overboot usually extends farther up the leg than the actual footwear, preventing snow from falling into the boot and slowing water that wicks down the trouser leg into the socks. A simple cloth or canvas overboot is not sufficient. Insulation must be provided in the overboot. Insulated overboots sometimes are heavy, usually are awkward both to put on and to carry when not worn, and often have slippery soles. Some insulating materials, once wet, hold water like a sponge and decrease the insulative properties markedly. Closed-cell foam plastic eliminates this problem. When the foot sweats in a completely waterproof overboot, the overboot does not dissipate the moisture and one soon has wet leather boots. Immediately on removing the overboot, the leather freezes and the whole problem of thawing a wet boot occurs. One frostbite case on Mount McKinley apparently arose from a similar situation when a regular boot got wet at low altitude and was never completely dried as the party climbed upward into colder conditions.

Many pre-war expeditions very successfully used shoepacs where melting might occur, changing to dry-tan moccasins, mukluks or felt shoes in temperatures of 10 °F. or colder. But two kinds of footgear are a nuisance and the softer cold-weather footgear was hardly ideal with crampons on very steep slopes.

The Army’s insulated “Korean” boot provides protection in a single piece of footgear. It is an insulated boot with a waterproof outer and inner lining. Korean boots have a high leg so that the protection extends well above the ankles. Models can be obtained that will accommodate crampons and that have a sole with fairly good traction. Some individuals have had a climbing sole with lugs put on, but they must be firmly anchored.

The biggest disadvantage of the Korean boot is that it does not breathe. Socks get wet because the boot retains all moisture. Some complain that it is unpleasant to have to slosh about while climbing and cases of trench- foot have occasionally occurred. It is obvious that changes of socks are essential. The boot is comparatively inflexible and never gets the comfortable feeling of a broken-in leather boot. Korean boots lose their insulative properties if the outer covering is punctured. Ice axes and crampons pose the biggest threat. A climber wearing them should carry a rubber patching kit and stop to repair a hole in the boot immediately so that the insulation does not become water soaked. Mainly because of the size and bulky construction, the Korean boot is excessively awkward for technical climbing. Recent models have better ankle support and allow more delicate climbing on steep ice. Carrying a second boot for technical use and a Korean boot for protection is one solution except that crampons fitted to one pair will not fit the other so that two sets of crampons must be carried too.

Unfortunately, there are different models of Korean boots with widely varying efficiency. Those types copying closely the military design (or of surplus vintage) perform well; many civilian so-called insulated boots do not incorporate the vapor barrier and insulation principle and perform badly. The second highest number of frostbite cases on Mount McKinley have been climbers wearing civilian-style insulated boots with poor protective qualities.

Arrangements which approximate the principles incorporated in the Korean boot also have proven satisfactory. One McKinley expedition carried a lightweight closed-cell foam overboot arrangement (home-made) with regular overboots. Putting the full rig on essentially converted their regular leather mountaineering boot into a Korean boot when frostbite protection was needed.

We have less evidence concerning the new double-boots, designed specially for high-altitude and cold climbing. The inner boot is made of some insulating material such as felt faced with leather. The outer leather boot slips over the inner boot. The combination is heavy, weighing about seven pounds per complete boot, about one pound more than the Korean boot. Some climbers carry an extra 2¼-pound inner boot to allow changing to a dry (or drier) pair. They presumably should be covered by overboots when needed. They do not have the advantage of a waterproof boot when trudging through low-altitude slush on the way to higher peaks. This again suggests two pairs of boots — one for wet snow and another for cold situations. On the other hand, why not carry plenty of socks and wear Korean boots which are good in both instances?

Is there an ideal boot that incorporates all of the necessary features to prevent frostbite and yet permits delicate climbing? Obviously not yet. The principle involved in the Korean boot provides the maximum amount of protection. For this reason, we in Alaska recommend it for arctic conditions, including climbs of McKinley and other high peaks. No one wearing military Korean boots on McKinley has been frostbitten. But they do not have the versatility required for the more difficult technical routes now being climbed on the mountain.

1. Bradford Washburn, "Frostbite, What it is — How to Prevent it — Emergency Treat- ment”, American Alpine Journal, 1962, 13:1, PP- 1-26. (This contains an extensive bibliography. )

2. American Alpine Club Accidents in North American Mountaineering, 17th annual report or the Safety Committee, 1964, pp. 2-3.