Which cooling mechanism is demonstrated by vapocoolant sprays?

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

Answer: (C)

Vapocoolant sprays cool primarily through evaporation. When the volatile liquid is sprayed onto the skin, it rapidly changes from a liquid to a gas. This phase change requires a large amount of energy, drawn from the skin in the form of heat—called the latent heat of vaporization. As the liquid absorbs this heat to vaporize, the skin temperature drops, producing quick, localized cooling. Conduction or convection would transfer heat differently (through direct contact or moving air, respectively), and radiation would involve infrared energy emission, not the main mechanism here. The dominant process is evaporation.