The predicted heat strain model considering wet and dynamic thermal insulation for thermal protective clothing: Modification and validation analysis

Abstract

For guiding the setting of working time, it is necessary to develop a realistic clothing model with accurate thermal physical properties including the effects of human body activities and environments in the predicted heat strain model, especially for the high thermal insulation clothing ensembles and high-temperature conditions. In this study, realistic clothing models, including clothing wet thermal insulation (I_{cl_w}), dynamic thermal insulation (I_{cl_vw}), and convective heat transfer coefficient considering the temperature difference and walking speed (h_{c_vw}), were established. Then, we validated the modified predicted heat strain models combined with realistic clothing parameters. The results revealed that the core temperature of the predicted heat strain model combined with I_{cl_w}, I_{cl_vw}, and h_{c_vw} (deviation of 0.1°C) was significantly more accurate than the original predicted heat strain model (variation of 1.5°C) in the environment of 40°C within 65 min of heat exposure. Our study emphasizes the necessity of ensuring the accuracy of clothing thermal physical properties in the predicted heat strain model to improve validity for the specific conditions investigated.