Visitors watch as Grigory Broverman, a member of the Cryophile winter swimmers club, pours a bucket of cold water over his 6-year-old daughter Liza during a flash mob, part of a celebration of Polar Bear Day at the Royev Ruchey Zoo in a suburb of the Siberian city of Krasnoyarsk, Russia, November 29, 2015. The air temperature was around minus 5 degrees Celsius. (Photo by Ilya Naymushin/Reuters)

Syrian refugee and Olympic swimmer Yusra Mardini is pictured during a training session in a pool at the Olympic park in Berlin, Germany on April 26, 2018. (Photo by Fabrizio Bensch/Reuters)

Tourists take photos from a panoramic viewing deck on Victoria Peak in Hong Kong, China, 26 January 2019. Hong Kong has been ranked the world's freest economy by the Heritage Foundation, a conservative research and educational institution based in Washington, for the 25th consecutive year, but the researchers also said the judiciary had become less effective. (Photo by Jerome Favre/EPA/EFE)

Dancers wearing traditional attires take part in the 7th Annual Ingoma Dance Competition organised by The Natal Playhouse theatre in Durban on March 21, 2017. The Ingoma Dance is considered one of the most purist forms of traditional Zulu dance. (Photo by Rajesh Jantilal/AFP Photo)

A Chinese People's Liberation Army soldier marches with members of an honor guard as they prepare for a welcome ceremony for visiting Luxembourg's Prime Minister Xavier Bettel outside the Great Hall of the People in Beijing, Monday, June 12, 2017. (Photo by Andy Wong/AP Photo)

A brick factory workers stack bricks on carts in Dhaka, Bangladesh, January 9, 2019. (Photo by Mohammad Ponir Hossain/Reuters)

A woman passes a mural in Manhattan on October 27, 2019 in New York City. (Photo by Johannes Eisele/AFP Photo)

Local people check the growth of mussels at a river in Haian County on November 2, 2017 in Nantong, Jiangsu Province of China. Fish, shrimp, crab and mussel farming cleans the river and increases the villagers' income at Haian county in Jiangsu. (Photo by VCG/VCG via Getty Images)