Prediction of physiological exertion in hot environments using the JOS-2 thermoregulation model

In recent years, the outdoor summer environment in Japan has become progressively warmer due to the severity of the heat island phenomenon. The danger of heat stroke and thermal comfort outdoors in summer are regarded as problems. In order to evaluate these problems, it is important to evaluate physiological exertion in the human body. The purpose of this research is to demonstrate the possibility of predicting physiological exertion in the human body with high accuracy in an outdoor environment during summer using the JOS-2 thermoregulation model developed by our research group. First, the Japanese metabolic rate in summer and autumn was measured for various activities, including sitting, standing, and walking. As a result, we found that the metabolic rate during sitting and standing was lower by about 10% in summer than in autumn. Next, using the obtained metabolic rate measurement as an input to the model, the experiment in an outdoor environment during summer was reproduced using JOS-2. The accuracy of the predicted mean skin temperature and local skin wettedness in an outdoor environment during summer was improved by choosing the appropriate input to the model.