One fifth of Earth is covered in snow and ice and these vast frozen landscapes are home to some of the wildlife wonders of the world.
Like this seal pup learning from its mother where to find the nearest breathing hole, or the Siberian tiger stalking through the snow, or Emperor penguin chicks gathering in Antarctica.
Polar ice sheets can be a staggering 5km thick, while on an East Antarctica plateau in the depths of winter, the air temperature can drop to minus 94C, making it the coldest place on Earth.
