When we touch a substance colder than we are, what takes place?
A part of the heat from us goes to that substance, and we experience a feeling of cold.
Does the amount of heat in any substance vary?
Yes; water may be heated until it is scalding hot, or the heat may be taken from it until it is frozen into ice.
What causes a substance to become cold?
Taking away heat from a substance causes it to become cold.
Then what is cold?
Cold is only the absence or want of heat.
When we pass from a very hot room to one moderately warm, how do we feel?
We experience a feeling of cold.