Often confused with heat and temperature, see how the two ideas are quite different, although they are closely related, of course.

The simplest to understand is the temperature. In an object, whatever it is, molecules, atoms that constitute it are not static. Instead, they move very quickly, but as they are small, we do not see it, of course.

This disorderly agitation of the particles of the object is called thermal agitation. The temperature measures the degree of agitation of the particles: more molecules of an object are agitated, the more it is hot. Less they move, the more it is cold. We measure the temperature in degrees Celsius or Kelvin. Or Fahrenheit.

For this reason, there is a minimum temperature, called absolute zero. The molecules of an object at absolute zero do not move at all. They are immobile. It can not descend below this temperature, since the molecules can not move less! This temperature is -273 degrees Celsius. We often measure the temperature of the coup in Kelvin (note K). The Kelvin and Celsius are roughly the same scale, shifted by 273 degrees. 0 ° C correspond to 273 ° K. O ° K is the absolute zero at -273 ° C.

Take a cold object and a hot object in contact. The molecules of the object are more agitated hot and bump them to molecules of the cold object. As a result, the molecules of the cold object begin to move faster, while those of the hot object is sluggish. It is said that the object gives hot heat to cold. Heat is the transfer of thermal agitation. It is different in temperature. The two objects, by exchanging the heat, change in temperature.

But we, what we feel when we touch an object, not the temperature directly, but the heat that this object gives us or takes us. Imagine a piece of metal and a piece of wood in the same room for a long time: they are at the same temperature. For against, when you touch the piece of metal, it seems colder. It is simply because it takes you over heat it conducts heat better, and may "contain" more. The piece of wood is at the same temperature, but it does not heat well.
Another proof is that something seems warm when it is warmer than your hands. And if not colder. We see much heat and not the temperature! To persuade you, put a hand in a bowl of hot water, a hand in a bowl of cold water, and then two in a bowl of warm water: one tells you that this water is cold and the other the water is hot!

Similarly, when someone walking on coals without burning, it does not sugnifie that coals are not hot. On the contrary. But rather than the person walking it does not get much heat. Coal leads one very badly heat ...