heat transfer

Last reviewed 01/2018

Heat transfer can occur from a body at high temperature to a region of lower relative temperature, by four physical processes:

• conduction: transfer of heat energy along a temperature gradient between objects that are in direct contact
• convection: a form of conduction in which a layer of air is warmed by direct contact with the body surface and is then displaced away. Movement away may be due to warm air rising or local breeze currents of air.
• evaporation: loss of heat from a body by using energy to vaporize water at its surface; important for physiological sweating
• radiation: transfer of heat from one object to another along a temperature gradient with no contact