Why can polar bears adapt to the cold weather in the Arctic?

Polar bears can adapt to the cold climate mainly because of their fur. Let's talk about its hair first. Its hair is not thick, but like duck hair, the outermost layer has grease, which can form a waterproof layer. It is not afraid of wind or water. Even if it swims in the water, the seawater can't touch the skin. What's more, its hair also plays the role of heat preservation and heat absorption. Scientists have found that its hair is like a hollow tube, just like the hollow of a thermos bottle, which can keep warm. These "insulation tubes" can only pass ultraviolet rays, which can convert 95% sunlight into heat energy and supplement heat for polar bear metabolism. Scientists once filled a flat solar collector with hair-like fibers and found that the efficiency of converting solar energy into heat energy increased by 50%. Awesome! Keep peeling it. The skin under its hair layer is black, close to the color of its exposed nose and paws. Among the visible light in nature, black absorbs heat best. Although the sunlight in the Arctic is weak, fortunately, it has black skin, and polar bears can absorb the sunlight to the maximum extent for their own use. What can resist the arctic cold is a "dermal" polar bear composed of hair, skin and fat. How cold can this leather resist? There was a record in the Arctic that the temperature dropped to 80 degrees below zero, and the polar bear is still alive, so it is no problem to see 80 degrees below zero. As for polar bears whose skin doesn't sweat like dogs at the highest temperature, their tolerance is not as good as that of humans. According to records, as long as it is at the age of 25. Stay in space for a while, and the lovely white fat man will go crazy! Source: Learning Guidance for Primary School Students _ Lower Grade of Fun Classroom