Polar bears are superbly insulated by blubber, the fat which is up to 4.5 inch thick. It certainly adds a layer of protection and can also be used for energy when food sources are minimal. Blubber also combines with the air trapping guard hairs to keep polar bears afloat in the water. The areas that lack the insulation are ears, tail and muzzle. These are especially small, minimizing non–insulated surface area to help prevent heat loss. Sometimes they cover their muzzles, which radiate heat, with their thickly furred paws.

Scientists have also seen polar bears stay warm by using the snow. Snow crystals trap small amounts of air, and polar bears will burrow in the snow to create an insulating blanket which, while cold, is still warmer than the outside world.