Polar bear. Thermogram of a polar bear (Ursus maritimus). A thermogram shows variation in temperature on the surface of an object, measured by the long-wave infrared radiation it emits. The temperature scale is colour-coded and runs from white (5.8 degrees Celsius, coldest) through yellow, red, purple and blue to black (warmest, 34.4 degrees Celsius). The polar bear is adapted to live in a cold environment. Heat loss from its ears is reduced because of their diminutive size. The bear also has a seasonal fat layer and thick fur which insulate it during the winter.