Reactions Release:
Heat is a form of energy, which is normally released or simply absorbed in reactions. Chemical reactions either absorb heat or release head. Coldness is just an indication for lack of heat.
Cold tells us that heat is absent. Reactions which release heat are known as exothermic reactions and reactions which require you to provide external heat (in order for the reactions to take place) are known as endothermic reactions.
One releases heat and the other absorbs the heat. Its about the thermodynamics and the nature of the reactions that take place.