Humans are able to control their heat production rate and heat loss rate to maintain a nearly constant core temperature ofTc= 37°C under a wide range of environmental conditions. This process is calledthermoregulation. From the perspective of calculating heat transfer between a human body and its surroundings, we focus on a layer of skin and fat, with its outer surface exposed to the environment and its inner surface at a temperature slightly less than the core temperature,Ti= 35°C = 308 K. Consider a person with a skin/fat layer of thicknessL= 3 mm and effective