COLD INJURIES - Medicine for Mountaineering and Other Wilderness Activities - page 388

viduals accidentally immersed in cold water can stay warmer by holding still to reduce
water movement and limit heat loss than they can by swimming to generate heat. (Unless
the shore or a boat is a very short distance away, active swimming in cold water should
be avoided.) Positions that limit the area of the body surface exposed to water also help
reduce heat loss. Two or more persons should huddle together to limit their contact with
water ( Fig. 26-2 ).
Conduction
Heat is conducted from the body when it is in contact with water, snow, rocks, or any
coldobjectthatisagoodconductor.Airisnotagoodconductor.Waterisanexcellent con-
ductor,andconductiveheatlossisamajorcontributortohypothermiaduringimmersionin
cold water.
Conductiveheatlossescanbecomesignificantinthewildernesswhenapersonisseated
or lying on ice, snow, or a cold rock. Another cause of conductive heat loss is lying or
sleeping on the ground without adequate insulation; foam pads eliminate much of the con-
ductive heat loss by this route. (Air mattresses, which allow air to circulate freely, provide
less insulation.) Although conductive heat loss alone is rarely a major cause of hypother-
mia, heat loss by this route can aggravate convective heat losses and should be avoided.
Conductive heat losses can become large when clothing is wet.