In energy balance for heat stress, which set of heat loss mechanisms is included?

• A. Sweat, evaporation, convection, and radiation.
• B. Metabolic heat production and environmental heat gain.
• C. Environmental heat gain and PPE usage.
• D. Temperature regulation only.

Answer: (B)

In heat-stress energy balance, think of the body as facing a heat load that must be shed to stay within safe temperatures. The total heat load comes from two sources: the heat the body itself produces metabolically, and heat that enters from the surrounding environment. These inputs determine how much heat the body needs to lose. The loss pathways—such as sweating (evaporation), convection, radiation, conduction, and respiratory heat loss—are the routes by which that load is dissipated, but the energy-balance terms that set the challenge are metabolic heat production and environmental heat gain. The other options describe loss methods or external factors, which are not the starting inputs to the energy-balance calculation.