A geometrically accurate 3 dimensional model of human thermoregulation for transient cold and hot environments.

This paper outlines the development of a finite element human thermoregulatory model using an anatomically and geometrically correct human body model. The finite element body model was constructed from digital Phantoms and is anatomically realistic, including 13 organs and tissues: skin, muscles, fat, bones, heart, lungs, brain, bladder, intestines, stomach, kidneys, liver, and eyes. The model simulates thermal responses through a passive and active system. The passive system describes heat balance within the body and between the skin surface and environment. The active system describes thermoregulatory mechanisms, i.e., vasodilation, vasoconstriction, sweating, and shivering heat production. This model predicts temperature distribution across the body at high spatial resolution, and provides insight into human thermoregulatory responses to non-uniform and transient environments. Predicted temperatures (i.e., core, skin, muscle and fat) at 29 sites were compared with measured values in comfort, hot, and cold conditions. The comprehensive validation shows predictions are accurate and acceptable.