Endotherm comes from the Greek roots “endon” meaning within and “therme” meaning heat. Just as its namesake suggests an endotherm regulates its own body temperature through metabolic processes. Endotherms generate more heat than exotherms because of a higher amount of mitochondria in their cells. Although being an endotherm can be advantageous in colder climates, these creatures often suffer from overheating. Adaptations such as panting and sweat have developed to stop this problem. Mammals, birds, some insects and fish are all endotherms. The dog in the picture above is an example of an endotherm.