I am a Physics graduate student at UC Berkeley, working with Professor David Romps in Earth Planetary Science Department. Our present work involves the interaction between climate and human bodies. Thermoregulation keeps a body warm at a constant temperature by metabolism and sweating. In the future, if the climate changes to some extent, we would like to know where and when the first human cannot survive in the severe surrounding. We use atmospheric simulation and physiology models to predict the condition when thermoregulation fails to work, especially under heat stress.