Ewan McGregor follows the cold chains, supplying vaccines to the world's hardest-to-reach children. Ewan first chooses a route that takes him through India. A country with a booming population and often on the move, the cold chain is a race against time to stop polio before it can spread. Ewan then ventures into the isolated wilderness of Nepal to reach a tiny community secluded high in the Himalayas.

Ewan McGregor follows the cold chain up the mighty Congo River, where he passes through frontier towns in the wilds of Central Africa, encounters a unique subculture for whom style is a religion, and ventures deep into the jungle in search of Pygmy tribes.