Nature tries to achieve a balance or uniformity, so wherever there is an excess of heat someplace (as in a high temperature region), heat will flow toward regions of low heat content (such as a colder area).

Conduction occurs from molecule to molecule. The distance between molecules is pretty small, so conduction is going to be slower than the next two processes to be described. Air is not as good a conductor as metal because air molecules move about randomly; thus the direction of motion of molecules that have had energy transferred to them may not initially go straight from someplace hot to someplace cold. Also, molecules in a gas are normally much farther apart and less orderly arranged than the molecules in a metal.