Maintaining temperature in extreme cold environments

Organisms in extreme temperature environments have different physiological and anatomical features that allow them to maintain a desired body temperature. In cold environments, many marine mammals have a thick layer of blubber to help insulate their bodies to stay warm. Not only does the blubber act as a thick insulator, but they also have a very integrative blood system which flows through the blubber to help maintain temperature and offer a high degree of control. Marine mammal’s flippers however are not layered with blubber. In order to keep their extremities warm in cold waters they have a counter-current heat exchange blood system. In the flippers each artery is surrounded by a system of veins. As cool blood flows from the extremities back to the heart it is warmed by the counter flowing warm blood from the heart to the extremities. Other ways for organisms to stay warm in cool environments includes: muscular activity, non-shivering thermogenesis, and an increased metabolic rate without muscular contractions.