movement of a fluid. Examples: a forced-air furnace and in weather systems.
* Radiation: heat transfer by microwaves, infrared radiation, visible light, or other electromagnetic radiation. An obvious example is the warming of the Earth by the Sun. A less obvious example is thermal radiation from the human body.

A hotter region experiences greater molecular agitation. When a hotter object touches a cooler surface, the molecules from the hot object bump the molecules of the cooler surface, transferring kinetic energy, heating the colder