In the first episode Ewan, who has been a Unicef ambassador for eight years, follows a route that takes him through India. In a country with a booming population, often on the move, the cold chain is a race against time to stop polio before it can enter the country and spread. From India, Ewan continues his journey into the isolated wilderness of Nepal. He must endure a gruelling two-day trek to reach a tiny community secluded high in the Himalayas, but not before attempting to land at one of the world's most dangerous airstrips.

• Ewan McGregor