Which is a form of passive cooling?

• A. Use of misting fans
• B. Rest in an air-conditioned environment
• C. Immersion in cool water
• D. Application of wet towels

Answer: (B)

Passive cooling means lowering body temperature without using mechanical devices or exerting extra effort. Resting in an air-conditioned environment fits this idea because the cool ambient air allows heat to move from the body to the surroundings through normal heat exchange, with no energy input or active cooling actions needed beyond simply resting.

Misting fans rely on a powered device to move air and promote evaporation, which makes them an active cooling aid rather than purely passive. Immersion in cool water involves direct contact with a cooler medium that actively pulls heat away from the body, a rapid and intentional cooling method. Applying wet towels also requires a hands-on step to introduce water and promote evaporation or conduction, so it’s an active form of cooling rather than passive.

So, resting in a cool, controlled environment best represents passive cooling because it leverages the surrounding conditions without additional tools or actions.