An extended individualized two-node human thermal model for high-temperature environments

Abstract

The human thermal model offers significant utility and advantages in predicting human heat strain. An advanced two-node human thermal model was proposed based upon Gagge's foundational to simulate individual physiological responses in high-temperature settings. This enhanced model incorporates the impacts of elevated temperatures on metabolic rate and the convective coefficient, and it accounts for individual variations in body surface area, the set points of body temperatures, and skin blood flow. Additionally, adjustments were made to the parameters representing clothing thermal insulation and vapor resistance. eight Chinese youths—four males and four females—were exposed to a high-temperature environment (35 °C/50 % RH) while wearing two different types of clothing to replicate light and moderate intensity activities to validate the model. The findings indicate that the model excels in predicting the thermal responses of individuals under this experimental condition. The maximal discrepancies between simulated and observed values for core and skin temperatures were confined to 0.3 °C and 0.6 °C, respectively. The model has been preliminarily demonstrated to reliably forecast individual physiological responses in given high-temperature environments. Nevertheless, the current framework does not take into account water loss in the human body, which is a key factor in long-term heat exposure. Looking to the future, more thermal regulation parameters can be comprehensively considered, and verified under various working conditions, so as to predict the thermal strain of the human body in high-temperature environments more comprehensively.