For this reason an objective measure of temperature is needed, and an objective definition of heat energy. Heat energy is the amount of energy a body has because of its temperature. A body at a temperature
\[\theta\]may contain a lot of energy or a little - the amount of heat energy in a body is equal to
\[E= mc \theta\], so depending on the values of
\[m, \: c, \: \theta\], where
\[m, \: c\]are the mass ans specific heat capacity respectively.
This is only a measure of ability to store heat. The ability to transfer heat depends only on temperature. A hotter body will always transfer heat to a colder body, so temperatures always tend to equalise. The human body has a temperature of 37 degrees, which is hotter than most of the objects that surround us. When we touch a piece of metal, the temperature is probably below 37 degrees, so we transfer heat to it, and very efficiently, because it is a metal, so it feels cool. When we touch a piece of fabric, even though it has a temperature below 37 degrees, we do not transfer a great deal of heat to it, because it is an insulator, and it feels (relatively) warm to the touch.