There are three ways in which heat can travel: conduction (which happens when materials touch), convection (which is the circulation of heat in liquids and gases) and radiation (which is the sending of heat rays, such as from fires and the Sun).

All warm-blooded animals, including us, have to control their body temperatures, not allowing it to get too hot or cold. We control our body temperatures mainly by heating or cooling our homes and by wearing suitable clothes.