Here's why:

* Deserts are defined by lack of precipitation, not temperature: While the Arctic is cold and dry, it does receive some precipitation, mainly in the form of snow.

* The largest deserts are in hot regions: The largest deserts in the world, such as the Sahara, are located in hot, dry regions.

* Antarctica is the largest cold desert: Antarctica, with its extremely low precipitation levels, is considered the largest cold desert in the world.

Let me know if you have any other questions!