Hand Skin Temperatures Associated with Local Hand Discomfort under Whole-body Cold Exposure

Abstract

This study aimed at pointing out the local thermal effects and subjective responses to cold air exposures of gloved hands in conditions of similar hand heat loss rates. Thirteen males and 13 females, lightly clothed (0.6 clo), participated in three separated experimental sessions (once a week), while sitting for 105 min in a climatic chamber at an operative temperature of 19°C. Subjects' hands were exposed in a ventilated cold box (air velocity=2.5 m·s−1) at one of three temperatures (8°C, 10°C or 14°C) depending on the dry heat exchange coefficient of the gloved hands. The temperature of the box was chosen to induce similar heat loss rates across conditions. Main results showed that local skin temperatures can be divided in 3 categories: 4 fingers (coolest), a thumb, back and palm (least cool). Female had lower skin temperatures than males but their local thermal discomfort was found to be similar for the same local skin temperature levels. As a consequence, the durations of the accepted exposures without discomfort were shorter in females. Discrepancies between male and female responses are discussed in terms of different hand skin blood flows. A practical aspect of our results concerns the glove thermal insulations which are obviously too poor at the finger levels, a factor determinant for discomfort occurrence in case of cold hand exposures.