How do polar bears keep their paws warm?

Polar bears have thick callused pads and fur on their paws to keep them warm. But this also provides traction so that the polar bear doesn't slip. The rest of the body of a polar bear is kept warm by a layer of fat sometimes called the blubber and thick fur. Polar bears are so well adapted to keeping warm that they need to cool off from time to time.

Last edited by Manabu Sakamoto (5th Feb 2007 13:14:47)

Hi Siobhan, Many animals also use countercurrent exchange of heat to keep warm. For example, the paws of the Arctic Fox. While the paws are necessarily cold, blood can circulate to bring nutrients to the paws without losing much heat from the body. Proximity of arteries and veins in the leg results in heat exchange, so that as the blood flows down it becomes cooler, and doesn't lose much heat to the snow. As the (cold) blood flows back up from the paws through the veins, it picks up heat from the blood flowing in the opposite direction, so that it returns to the torso in a warm state, allowing the fox to maintain a comfortable temperature, without losing it to the snow.