Why polar bears are not easy to freeze to death in the cold Arctic?

Polar bears are stationed in the vast ice area between 80 degrees and 85 degrees north latitude all the year round. When we say that they are resident, we mean that they never leave the bitter and cold place in the extreme north all year round, whether it is extreme day or night, whether it is foraging or breeding. Polar bears are complete carnivores and have no plants in their diet. This can't blame its unhealthy eating habits, which is forced by the harsh environment in the Arctic. Native arctic plants, mainly mosses and lichens. At the lower latitudes of the Arctic, you can occasionally see a drop of green, and at the higher latitudes, almost nothing grows. Polar bears can only eat pure meat all their lives and live alone in the ice and snow. It may be the loneliest animal on earth. If the Arctic ice floes melt, or even there is no ice, polar bears will lose their homes and cannot survive. Someone asked an animal expert: "Can polar bears immigrate to the South Pole, let them adjust their diet and practice eating penguins from now on?" The animal expert said, "Polar bears don't want to leave the North Pole." Source: Special Summary