Heat and life: the ongoing scientific odyssey

The source of body heat has fascinated philosophers and scientists for millennia. Resting heat production is a major component of human energy requirements in health and disease. This review traces through mankind's attempts to understand the nature of resting heat production in humans and animals and its relationships to body mass and composition. Far from being fully understood, the study of heat production is an area of intense research interest bridging the gap between modern biology and physics.