(10) Nutrition. Starvation or semistarvation predisposes to cold injury.
Adequately clothed and protected personnel in cold climates do not require more than
the normally provided military ration of 3600 to 4600 calories per day. Evidence of a
need for specific nutrients in the diet for cold injury or treatment is lacking. However,
the increased exercise requirements imposed by heavy clothing and equipment and the
increased difficulty of movement in snow-covered terrain can increase caloric
requirements up to 7000 per day. For example, cross-country skiing can require the
expenditure of between 600 to 1200 calories per hour.
(11) Activity. Too great or too little activity may contribute to cold injury.
Overactivity can cause the loss of large amounts of body heat by perspiration. The
perspiration becomes trapped in excess clothing thus reducing the insulating quality of
the clothing. On the other hand, immobility causes decreased heat production and the
danger of cooling, especially in the extremities and pressure areas of the body.
effects on circulation or sweating when prescribing drugs and medication in cold
climates. Morphine is an important example of a drug with a significant effect on
cutaneous (skin) circulation and, therefore, on body heat balance. Chlorpromazine,
barbiturates, and clopenthixol are other drugs which can predispose to cold injury.
(13) Alcohol. Because of its questionable vascular effects, coupled with its
influence or judgment, alcohol should be avoided under conditions of extreme cold. The
dangers of hypothermia and frostbite are increased greatly under its influence.
5-3.
DEGREES OF COLD INJURY
Early evaluation of the severity of injury is extremely difficult even to the most
experienced medical officer. Definitive classification of severity of cold injury into first,
second, third, and fourth degree is possible only in retrospect, after the case is
completed. However, since at the two extremes, there can be some clinical distinction,
this classification has some value.
a. First Degree--Hyperemia and Edema.
(1)
After rewarming, skin becomes mottled, cyanotic, red, hot, and dry.
(2) Apparent hyperemia (excess of blood in a part), blanches (becomes
lighter) poorly when pressed, and capillary filling is sluggish or absent.
(3)
There frequently is intense itching or burning; later, there is a deep
seated ache.
(4) Swelling begins within three hours and may persist for ten more days if
the individual remains on duty.
MD0587
5-6