Finger numbness after acute local exposure to cold

Abstract

Twenty subjects exposed the index finger to air at –22°C and a wind speed of 300 ft/min. until the indicated skin temperature fell to –5°C. The finger was then returned to room temperature conditions (19°C) and the subject tested on each of two tasks involving tactile discrimination until the finger had fully recovered. The degree of impairment on both sensori-motor tasks at a given skin temperature varied appreciably from subject to subject, although most subjects showed little impairment above about 8°C. The evidence suggests that while finger numbness as measured by Mackworth's V-test may indicate a corresponding impairment of performance in accuracy of pressure reproduction, testing subjects on either task at normal skin temperature will have little predictive value for their relative performance after cold exposure in the present situation. Submitted on December 24, 1958