Endotherm vs. Exotherm

Endothermnoun

(biology) an animal that maintains a constant body temperature

Exothermnoun

(chemistry) Any exothermic compound

Endotherm

An endotherm (from Greek ἔνδον endon and θέρμη thermē ) is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions instead of relying almost purely on ambient heat. Such internally generated heat is mainly an incidental product of the animal's routine metabolism, but under conditions of excessive cold or low activity an endotherm might apply special mechanisms adapted specifically to heat production.

‘within’; ‘heat’;