“With their thick hides and lack of sweat glands, it has long been thought that elephants rely upon their distinctive large ears and bathing in rivers to stay cool in hot climates.
“New research, however, has revealed that the world’s largest land animals have a secret trick to control their own body temperatures…
“By directing their blood supply near the surface of small patches of skin scattered around their bodies, elephants can lose heat rapidly, allowing them to fine-tune their internal temperature.” (Gray 2010)
Elephants use 'hot spots' to stay cool
“In this study, we examined infrared thermograms in the course of time of six African zoo elephants and observed two phenomena. First, we noticed independent thermal windows, highly vascularised skin areas, on the whole elephants’ body and second we observed distinct and sharply delimited hot sections on the elephants’ pinnae. The frequency of thermal windows increased with increasing ambient temperature and body weight. We assume that the restriction of an enhanced cutaneous blood flow to thermal windows might enable the animal to react more flexibly to its needs with regard to heat loss. With this understanding, the use of thermal windows in heat loss might be seen as a fine-tuning mechanism under thermoneutral conditions.” (Weissenböck et al. 2010:182)