Which of the following is a heat loss mechanism described in the material?

• A. Evaporation of sweat
• B. Metabolic heat generation
• C. Shivering
• D. Vasoconstriction

Answer: (A)

Evaporation of sweat is a heat loss mechanism because when sweat evaporates from the skin, it absorbs a large amount of heat from the body to change liquid water into vapor. This latent heat of vaporization provides a powerful cooling effect, helping to lower body temperature during exercise or heat exposure. In contrast, metabolic heat generation increases internal heat production, shivering boosts heat through muscle activity, and vasoconstriction reduces heat loss by narrowing skin blood vessels. So the sweating process is the key way the body actively loses heat.