Humans Can Lose, but Cannot Gain, Heat Through the Process

Question

Humans can lose, but cannot gain, heat through the process of
A) conduction.
B) convection.
C) radiation.
D) evaporation.
E) metabolism.

Accepted Answer

Humans lose heat through the process of evaporation when they sweat. However, humans cannot gain heat through this process. Conduction, convection, and radiation all involve the transfer of heat from a warmer object to a cooler object, so they can either contribute to heat loss or heat gain. Metabolism is the process by which the body converts food into energy, and it can generate heat as a byproduct, so it can lead to heat gain. Therefore, the only process that fits the criteria of heat loss without the potential for heat gain is evaporation.