Auxiliary Heating of the Hands during Cold Exposure and Manual Performance

Twenty subjects performed five manual tasks barehanded during exposure to a 60°-F ambient temperature control condition, a 0°-F condition, and three ambient temperature conditions of 20°, 0°, and −20° F, in which auxiliary heat was applied to the hands. The tasks consisted of the Purdue Pegboard assembly, block-stringing, Minnesota Rate of Manipulation placing, knot-tying, and screw-tightening tasks and were performed after exposure durations of 0, 60, 120, and 180 min. Exposure to the 0°-F condition without auxiliary heat resulted in significant performance decrements on all tasks. The application of auxiliary heat to the hands resulted in the avoidance or alleviation of impaired performance during cold exposure depending upon the task, ambient temperature condition, and duration of exposure. The differential effects of auxiliary heat during cold exposure across manual performance tasks were related to the effects of auxiliary heat on hand skin temperature. These effects are discussed in terms of differential hand and finger dexterity, strength, and speed of movement requirements across tasks.