Natural Radiators

Keeping cool becomes a challenge in tropical areas, especially when animals are larger or more energetic. Natural radiators are an efficient way of lowering the body’s temperature: for instance, the ears of the elephant and the rabbit are full of blood vessels, helping the animal cool its body in the heat. Rabbits living in Arctic areas have smaller ears, and so did the woolly mammoths, in order to protect themselves from the cold. Radiators were encountered in the prehistoric world as well, in animals such as the Dimetrodon of the Permian, or, according to some scientists, dinosaurs belonging to the Stegosaurus family, the plates of which would have been highly vascularized in order to permit heat exchange.