Serious Arctic - Episode 3

Eight young people go to extremes to help the planet, undertaking a marathon dog-sled journey in the Canadian High Arctic to help endangered polar bears. Morale plummets as the team tries to build igloos in the harshest conditions it has faced so far. Wind chill takes temperatures well below minus 40, and homesickness sets in. Meanwhile, one lucky team member takes part in an aerial survey of rare whales.