Heat transfer

Heat radiation

Every object that that has another temperature than 0K (Kelvin) emits radiation. These rays are called heat or temperature radiation. The higher the temperature of an object the more radiation it emits.

An object emits not only heat but also receives radiation from its environment (sun, other objects, walls, furniture and so on). An object cools down when it emits more heat radiation than it receives from its environment. An object heats up when it receives more heat radiation from its environment than it emits.