People enjoy a bath in hot kvass, a traditional fermented beverage made from rye bread, during the sauna marathon near Otepaa, Estonia, February 6, 2016. Participants have to track down and visit the given saunas in the Otepaa area as fast as possible. (Photo by Ints Kalnins/Reuters)

A man sleeps between tombstones in front of his single-room home on a hot night in the Cairo Necropolis, Egypt, October 13, 2015. In the sprawling Cairo Necropolis, known as the City of the Dead, life and death are side by side. Amid a housing crisis in Egypt, and with the population of greater Cairo estimated at about 20 million, people count themselves lucky to have a place to call home in the graveyards that date back hundreds of years. (Photo by Asmaa Waguih/Reuters)

A young Hindu girl sits for a ceremony where she and other girls are worshipped as “Kumari”, or living goddess, during Ram Navami festival, at a temple in Kolkata, India, Saturday, March 28, 2015. Ram Navami marks the birth of Hindu God Rama. (Photo by Bikas Das/AP Photo)

Students celebrate their A-level results at King Edward VI High School for Girls in Birmingham, England on August 18, 2016. The proportion of top grades achieved by A-level students across the UK has fallen for a fifth year in a row, and girls have caught up with boys in attaining A* grades. (Photo by Joe Giddens/PA Wire)

A girl plays with coloured chicks for sale prior to Easter celebrations in Byblos, Lebanon on March 22, 2015. (Photo by Jamal Saidi/Reuters)

“Harajuku is a district in Shibuya ward, Tokyo Prefecture”. – Wikipedia. Photo: Harajuku Girl Photo Shoot. (Photo by Tokyo Fashion)

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A girl gets a helping hand across the road in Swansea, Wales, England on December 31, 2017. (Photo by Athena Picture Agency)