Adelie penguins live their whole lives near ice. Warming temperatures have meant less sea ice, and Adelie penguin numbers are in decline at their traditional colonies.

In winter, polar bears hunt for ring seals, which hide beneath the sea ice near breathing holes. Long summers with no ice are likely the main reason why many polar bear populations are dropping.

Military submarines have been measuring the Arctic ice cap since the beginning of the Cold War. What they’ve discovered is startling. According to their measurements, the thickness of the ice cap has diminished by half since 1980.

Inuits of Northeast Canada take advantage of extreme tides to gather mussels beneath the sea ice. They only have 30 minutes before the tides rush back in.

Under the ice and snow of Antarctica's only active volcano, Mount Erebus, lies a network of caves harboring incredible ice formations that occur nowhere else on earth.

The Chukchi, natives of the Arctic, risk life and limb to collect guillemot eggs from the side of a sheer cliff in the Arctic. Over the years, many men have fallen to their deaths doing this.

A Frozen Planet cameraman has been trying to film an eider duck hatching her ducklings, but with varying degrees of luck, including a run in with a polar bear.

Spending months surrounded by nothing but penguins could drive anyone mad. Two Frozen Planet cameramen try to hold on their sanity at an Adelie penguin colony in Antarctica.

Growing up polar bear isn't all fun and games (although, that's part of it too). Polar bear cubs are forced to face some pretty big shocks in their first year in order to survive.

Frozen Planet series producer Vanessa Berlowitz reveals what it's like for a woman to go to the bathroom in the poles. As challenging as it is normally, all modesty goes out the window when there are hungry polar bears about.

Frozen Planet came at a time of great breakthroughs in high speed photography, in time lapse and in digital storage capacity. All these jumps in technology were vital to capturing the incredible worlds of the poles.

Dr. Faye Hicks has been studying river ice and ice flooding for years. She helped Frozen Planet predict when Canada's Hay River would break up, a scene depicted in the "Spring" episode.

To capture the dramatic break up of the Hay River in Canada, Frozen Planet filmmakers had to first pinpoint when it was supposed to start. Enter river ice scientist Faye Hicks, who uses science to predict these annual events.

The Frozen Planet film crew gets as close as they safely can to capture spectacular shots of polar bears and their cubs.

These camera men witness something truly spectacular. While trying to attract the attention of just one killer whale, they are able to spark an interest in many different nearby orcas.

A migration of eider ducks interrupts a filmmaker's report to camera that the first shoot of Frozen Planet is "beginning to look like a failure". He ends up getting spectacular aerial footage of 500,000 eider ducks.