Heat is a form of energy, and the quantity is measured in the same units as any other form of energy. The SI unit of energy, the joule, is applied to heat as well as any other energy. As for the quantities of heat transferred, it does not matter by what physical process the heat is lost. The critical parameters are the initial and final temperatures, giving a temperature difference, and the specific heat and volume of the material from which the heat is lost.

As a working example: the calorie is defined as the amount of energy required to raise the temperature of 1g of water by 1ºC, so raising the temperature of 100ml (100g) of water from 20ºC to 25ºC requires 100 x 5 = 500cal. Otherwise expressed: the specific heat of water is 1cal/g. Aluminium has a specific heat of 0.215cal/g, meaning that to heat aluminium one needs much less heat. To heat an aluminium block weighing 100g through 5ºC requires only 100 x 5 x 0.215 = 108cal. 1cal = approx 4.2joules.

Thespecific heatis the amount ofheatper unit mass required to raise the temperature by one degree Celsius. The relationship betweenheatand temperature change is usually expressed in the form shown below where c is thespecific heat. ... As a result, water plays a very important role in temperature regulation