What is conduction?

• A. Transfer of heat from one material to another through direct contact
• B. Transfer of heat via currents of air or water
• C. Emission of heat by radiation
• D. Evaporation of moisture from skin

Answer: (A)

Conduction is the transfer of heat between materials that are in direct contact. When a hotter object touches a cooler one, energy moves from the warmer to the cooler object through molecular interactions and collisions, until temperatures even out. In practice, this is what happens when a patient’s skin touches a cold bed, a metal stretcher, or an ice pack applied to the skin—heat moves by direct contact. This is different from convection, where heat moves through currents of air or water around the body; radiation, where heat is emitted as infrared waves without contact; and evaporation, where cooling occurs as moisture on the skin turns to vapor.