A modified multi-node human thermoregulation model with improved sweating response to simulate human physiological behaviours in warm and hot environments

Abstract

The present research developed a modified multi-node thermoregulation model derived from the renowned Tanabe and JOS series models (JOS-2 and JOS-3). The JOS-3 model's predictions showed an abrupt spike in mean skin temperature, contradicting the findings from experiments. The JOS-3 model's sweating mechanism exhibits an inconsistency, and the sweating mechanism is not triggered promptly and accurately, leading to a sudden rise in skin temperature. This disparity significantly impacts the ability of the model to precisely replicate thermoregulatory responses under various climatic conditions and levels of physical activity. The proposed modified thermoregulation model extends the JOS-3 model by modifying the set-point temperature and sweating signals. The performance of the developed modified thermoregulation model is thoroughly analyzed under various conditions involving different environmental conditions, activity levels, and clothing types. The proposed model eliminates abrupt rise in the mean skin temperature and improves its prediction accuracy, notably reducing mean skin temperature RMSE in hot-humid conditions (0.66 °C vs. 0.85 °C) compared to the JOS-3 model. In hot-dry settings, improvements are significant, reducing the mean skin temperature and core temperature RMSE (0.48 °C vs. 0.06 °C and 0.05 °C vs. 0.02 °C, respectively). Overall, the modified thermoregulation model offers a reliable and accurate solution to analyze human physiological conditions for a wide range of practical problems.