Animals keep warm in coats of many colours

Some people do not mind the cold. They just put on an extra coat, thick trousers and a scarf to keep warm.

But what about animals? What do they do to keep warm if they do not hibernate or migrate? Steam bath in the snow: Imagine lying in a hot bath in the open air with snow and ice all around. The Japanese macaques, or snow monkeys of northern Japan, nip into natural hot springs to enjoy a bath during harsh winters. It must be a shock climbing out into the freezing snow.

The furry blanket: The animal with the longest hair in the world is the musk ox.

Its fur can grow to nearly one-metre long. Imagine having to comb through that.

The coat traps a layer of still air next to the skin. There is also an extra layer of soft, warm fur under the straggly, waterproof outer layer. The musk ox looks as if it is draped with a shaggy, old rug.

The Arctic giant: The huge polar bear is larger than its relatives - the grizzly and black bears which live in warmer lands.