The snow in bear tracks is not melted, so it seems they let their feet get cold when they are walking (probably when swimming, too). I suspect the flow of blood is regulated to keep the feet from getting frozen, but too cold to melt snow. My experience is with Alaska brown bears, but they are very close relatives of polar bears.
Umm...where did the writer suggest that penguins and polar bears came from the same place? Must have missed that one.With regard to the snow not melting, could this also be because the heat from the bears#39; paws is insulated behind the layer of fur that grows from them?