A fire spreads by transferring heat energy in three ways: Radiation, Convection, and Conduction. Radiation refers to the emission of energy in rays or waves. Heat moves through space as energy waves. ... Convectionis the transfer of heat by the physical movement of hot masses of air. Conduction is the passage of heat energy through or within a material because of direct contact, such as a burning wastebasket heating a nearby couch, which ignites and heats the drapes hanging behind, until they too burst into flames.