Which process is described as heat loss through vaporization of water from the skin?

• A. Evaporation
• B. Radiation
• C. Conduction
• D. Convection

Answer: (A)

The main concept is heat loss through vaporization of water from the skin, which is evaporation. When water on the skin turns into vapor, it absorbs latent heat from the skin and surrounding tissues, causing cooling. This is the mechanism behind sweating and how the body sheds heat during hot conditions or exercise. Other forms involve heat transfer without a phase change: radiation is heat emitted as infrared energy from the skin to the surroundings, conduction is heat transferred through direct contact with a surface, and convection is heat carried away by moving air. Evaporation uniquely relies on converting liquid water to vapor and using latent heat, making it the correct description for heat loss via water vapor from the skin.