Often the concepts of heat and temperature are thought to be the same, but they are not. Perhaps the reason the two are usually and incorrectly thought to be the same is because as human beings on Earth everyday experience leads us to notice that when you heat something up, say like putting a pot of water on the stove, then the temperature of that something goes up. Turns out, though, this is not true. Initial Definitions Temperature is a number that is related to the average kinetic energy of the molecules of a substance. If temperature is measured in Kelvin degrees, then this number is directly proportional to the average kinetic energy of the molecules.
Heat is a measurement of the total energy in a substance.
That total energy is made up of not only of the kinetic energies of the molecules of the substance, but total energy is also made up of the potential energies of the molecules. So, temperature is not energy. It is, though, a number that relates to one type of energy possessed by the molecules of a substance. Temperature directly relates to the kinetic energy of the molecules. Temperature readings do not tell you anything directly about this potential energy.