Endotherm
An endotherm is a warm-blooded animal (such as homo sapiens).
Another term for us warm-blooded creatures is homeotherm.
An endotherm or homeotherm is as opposed to a poikilotherm (an organism such as a frog that is cold-blooded) and a stenotherm (a creature that can only survive only within a very narrow temperature range).
Endotherm is entirely Greek (as to origin).
The Greek 'endo-' means 'within' + '-therm' is from the Greek 'therme' meaning 'heat' = the heat within.