Warmth - part 2

Articles In This Section:

· Warmth - part 1

· Warmth - part 2

· Warmth - part 3

· Warmth - part 4

Conserving body heat.—Much more can be done in conserving heat than in producing it. In the first place, the body itself possesses certain mechanisms for this purpose. We are all familiar with perspiration and evaporation as a means of cooling. We are not so familiar, however, with the fact that the skin automatically shuts off surface blood circulation when exposed to cold, and that this action decreases the heat loss from the skin to one-fourth of normal. This reaction alone goes a long way toward enabling a skier to keep warm. Alcoholic drinks prevent this thermostat from properly functioning and therefore result in rapid loss of heat from the body. For this reason, the inflexible rule of ski mountaineering is that alcohol should never be drunk during or immediately previous to exposure to cold. As the body continues to get colder, the next reaction of the human system is to cut off most of the blood supply which normally goes to hands and feet and thus attempt to preserve normal temperature within the torso, where the vital parts of the body are situated. This can reduce the blood supply to the hands to as little as one-eighteenth of maximum. The danger of freezing of hands and feet as a result of such general chilling is obvious. In practice then, if danger of freezing the extremities exists, it is just as necessary for the skier to put on an extra sweater as dry mitts or socks; moreover, the sweater, unlike extra socks, cannot cramp circulation in the feet.

Wind is as important as low temperature in producing chilling. A ten-mile-an-hour wind under some conditions is equivalent to a lowering of the external temperature 60°. On increase of wind velocity above ten miles per hour produces little additional cooling effect if wind-proof garments are worn.

The problem of keeping warm is then primarily the providing of insulation from both wind and cold.

To provide insulation from wind:

1) A sheltered spot should be selected for camp.

2) The tent should be thoroughly windproof. Because of the large amount of air that filters through ordinary tent walls, coated waterproof fabrics are warmer in heavy winds than the closest woven permeable cloths.

3) In a heavy wind a snow cave is warmest because it alone can provide still air, although the snow is usually porous enough to allow adequate ventilation.

4) Clothing should consist of a thin, windproof outer shell and as many inner garments as may be required for warmth. This windproof shell usually consists of a parka, a face mask (under extreme conditions), outer mitts of leather or fabric, and windproof trousers, either wool gabardine ski pants or special trousers over usual ski pants. Ski boots complete this shell. Windproof joining of these articles of clothing should be provided: a sewed-on parka hood, adequate parka drawstrings for face and waist, straps on cuffs of outer mitts and the usual tight-bottom ski pants.