Polar bear. Thermogram of a polar bear (Ursus maritimus) with its mouth open. 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 (-1.0 degree Celsius, coldest) through green, yellow and red to black (warmest, 34.9 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 that insulate it during the winter.