Direct transfer of heat through contact with a cooler surface is known as which mechanism?

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

Answer: (A)

Conduction is heat transfer by direct contact with a cooler surface. When two objects touch, their particles collide and energy moves from the warmer object to the cooler one, until their temperatures balance. In EMS and patient care, this explains why a patient loses heat when lying on a cold gurney or gains heat from a warm blanket through touch. This differs from convection, which involves heat carried by moving fluids or air; evaporation, which is heat loss as moisture changes to vapor (like sweat evaporating); and radiation, which transfers heat through infrared waves without direct contact.