ISSA Nutritionist Practice Exam

Which of these processes describes the main method by which the human body dissipates heat?

1. Conduction

2. Convection

3. Evaporation

4. Radiation

The correct answer is: Evaporation

The main method by which the human body dissipates heat is through evaporation. This process is particularly important during physical activity or in hot environments. When the body temperature rises, sweat glands produce sweat, which is primarily composed of water. As this sweat evaporates from the skin's surface, it requires energy, which is taken from the body in the form of heat. This cooling mechanism helps to regulate body temperature, preventing overheating and allowing for optimal physiological functioning. While conduction, convection, and radiation also play roles in heat dissipation, evaporation is the most effective, especially at higher temperatures. Conduction refers to the transfer of heat through direct contact, convection involves the movement of heat through fluids (like air or water), and radiation occurs when heat is transferred through electromagnetic waves, but these processes are not as significant in the context of temperature regulation compared to evaporation.