Effect of phase change cooling vest on related thermal regulation factors in moderately hot environments

Abstract

Phase change cooling vests (CV) are mostly developed to improve people's thermal comfort in warm or hot environments. In this paper, the effect of a CV on related thermal regulation factor was studied. Physiological parameters (including skin temperature, sweat rate, fingertip blood flow, and ear canal temperature) and conductive heat flux were measured in three air temperature conditions (27, 29, and 31 °C). Results found that compared with no cooling vest (NCV) conditions, the maximum decrement in local skin temperature for the back and chest with CV was 2.5 and 2.1 °C, and for the mean skin temperature (Tmsk), the decrement was 0.8 °C. Simultaneously, the mean conductive heat flux of the back and chest with CV was significantly increased by 28.3% and 234.4%, respectively (p < 0.01). The total sweat rate (SR) of subjects using CV was decreased by 14%–18%. The SR of the forehead was positively correlated with the overall thermal sensation and comfort. With the use of CV, the fingertip blood flow (Qfinger) tended to decrease. As the experimental temperature elevated, the impact of the CV on Qfinger was more effective. However, there was no difference in Qfinger and ear canal temperature between the CV and NCV conditions. The results provided a better understanding of the improving effect of CV on human thermal comfort from the perspective of thermal regulation.