Participants take part in the 2019 Baikal International Ice Skating Marathon on Lake Baikal, the world's deepest freshwater lake, on March 2, 2019. Many male participants only wear underwear despite the extreme cold. [Photo: IC]"

A participant plays ice hockey on Lake Baikal, the world's deepest freshwater lake, on March 2, 2019. [Photo: IC]"

A young participant takes part in the 2019 Baikal International Ice Skating Marathon on Lake Baikal, the world's deepest freshwater lake, on March 2, 2019. [Photo: IC]"

A shirtless participant skates at the 2019 Baikal International Ice Skating Marathon on Lake Baikal, the world's deepest freshwater lake, on March 2, 2019. [Photo: IC]"