How do polar bears stay warm?
Polar bears stay warm with a thick layer of fat, up to about 10 centimeters, and dense fur with two layers. Their black skin may also help absorb heat from the sun.
Polar bears live in the Arctic, where winter temperatures can drop below minus 40 degrees Celsius. A layer of blubber under the skin insulates their bodies and stores energy. Their fur has a dense, woolly underlayer and longer outer guard hairs that shed water and trap warm air close to the skin.
Polar bears are so well insulated that they rarely lose heat. In fact, they are more likely to overheat, especially when running. Their small ears and short tails reduce heat loss, and fur on the soles of their feet helps them grip the ice and stay warm.
Swimming in icy water
Polar bears are strong swimmers and can swim for days across open water. Their fat helps them float and stay warm in the freezing sea. As Arctic sea ice melts earlier each year, polar bears must swim farther, which uses up their energy.
Did You Know?
Polar bears are classified as marine mammals because they spend so much of their lives on sea ice and in the ocean.