I recently spent two years in the Arctic filming the series Blue Planet. I love being in an environment that hasn't changed for 20,000 years. Of course it's freezing, but it must be a healthy place because you never catch colds.

When I'm filming, I like to really feel how lonely the environment is. Filming underwater involves cutting through thick ice and diving in tied to a line. The person at the other end has to be ready to pull you out fast if necessary.