Located in close proximity to the Polar Circle, Iceland experiences extreme winters. Cold weather and, above all, darkness invade the daily lives of the 300,000 Icelanders, whose organisms must adapt to these conditions. They appear, however, to have an excellent resistance to them, given that the rates of Seasonal Affective Disorder are lower that those in the other countries on the same latitudes.
Bernard travels to the Island of Fire and Ice to understand how its inhabitants have adapted to their extreme environment. Remedies to weather the long polar night include hydrotherapy, light therapy, social connection, and the consumption of cod liver oil.