Abstract
The aim of this research is to propose a model for predicting heart rate in hot environment by applying our model for predicting body temperatures (both core and mean skin temperature), sweating rate. The predicted body temperatures and heart rate will be used as an index for evaluating hot environment, and for protecting people working and exercising from a physiological disorder caused by heat. In this paper, we have proposed an equation on heart rate expressed as a function of skin temperature and VO_<2max> considering an individual variability of athletic performance. The variation of human sweating rate has appeared not only between individual subjects but also between the same subjects.