One of the most important animal in this area is the reindeer. It is well known by many people because of its role in the stories about Santa Claus. It has also played an important role to keep people alive, providing us with food, transportation, shelter and clothing. In Sweden there are no wild reindeer anymore, all reindeer are owned by Reindeer herders, most of them Sami people. The only wild reindeer in Europe can be found in Norway. The total population of mountain reindeer (or wild reindeer) in Norway is about 25 000, a small amount compared to the 200 000 of ‘domestic’ reindeer herded by the Sami people in Norway. The reindeer is made for long, cold winters. Every part of the reindeer has hair, even the mule is hairy. The hair is hollow, which gives an extra insulation because there is air in it. It even has a special heat exchanger in the legs so that the cold blood from the hooves is warmed before it reaches the heart. Also, the nasal cavity has lots of blood vessels which enables the cold air from outside to get warm and the loss of heat from the exhalation is minimized.