Nature is amazing and with winter quickly approaching, this programme takes a look at some of the natural wonders of one of the chilliest parts of the world. Gordon Buchanan, Kate Humble and Simon Reeve head out to Churchill in Canada, Alaska, and Greenland respectively. Across a three day-long expedition, they follow polar bears and other wildlife which are on their winter hunt and trying to make a home out of the harsh landscape. The first of the three-part series airs tonight and sees Churchill-bound Gordon learn how to stay safe while living side by side with the world's largest living land carnivore.