The influence of upper body skin temperatures in the regulation of sweat secretion in man

The purpose of this investigation was to determine the role of four upper body skin regions in the regulation of thermal sweating. Eight male subjects were exposed to two environments during which the local skin temperature (T^ki) four skin regions (head, upper arm, forearm and hand) were elevated or reduced by 3°C from a neutral temperature. Body core and skin temperature were recorded from multiple sites, while sweat rate were simultaneously measured at eight skin regions. Sweat rate was found to increase both at the site of local temperature change and at the other seven sites. Between-site differences were not significant, and there were no contralateral affects, suggesting that changes in T,ki were centrally integrated, affecting sweat rate at all body surfaces equivalently. Afferent input from the head dominated the regulation of thermal sweating. The hand was equally sensitive, while the least sensitive site was the forearm. These data reflect either differences in local thermoreceptor densities or an hierarchical treatment of cutaneous thermoreceptor inflow.