Effect of rate and level of lowered finger surface temperature on manual performance.

Thirty-two subjects were tested on six manual tasks when the right forefinger surface temperature was either not lowered, for the control condition, or lowered to temperatures of 65, 55, and 48 F after 5 or 50 minutes of cooling. Performance on all tasks decreased with lowered surface temperature. The level of finger surface temperature associated with impaired performance and the extent of the performance decrements associated with additional cooling varied across tasks and cooling rate. The differential effects of local cooling on manual performance across tasks and cooling rates were analyzed in terms of the differential susceptibility of hand function to parameters of cold exposure and the selective requirements across aspects of manual performance for unimpaired functioning of the hands and arms.