Seasonal variation of dynamic properties in sweating activity

Abstract

Seasonal variation of sweating response to the thermal stimuli was investigated by the power spectral analysis. Both the summer and winter experiments were performed on the same subjects. The sweat rate was measured by using a sweat capsule, and was analyzed by the fast fourier transform. In the spectra obtained, the low frequency components for the summer were larger than for the winter, and each of the peaks in the power spectra for the summer was shifted to the higher frequency from the corresponding peak for the winter. This shows the adapted changes in the rhythm of thermoregulation to the heat acclimatization. As a result of the examination for the frequency distribution of the sweat rate, the frequency component at 0.02Hz for the summer was found to be larger than that for the winter. This component was significantly correlated to the blood flow, so it suggests that the seasonal variation of dynamic property in sweating activity is affected by the blood flow.