Visitors crowd an artificial wave swimming pool at a tourist resort to escape the summer heat in Daying county of Suining, Sichuan province, China, July 11, 2015. (Photo by Reuters/Stringer)

Biologist Kelly Martin records her measurements of Electra, a 5 1/2 foot leatherback turtle nesting on the beach behind the Seminole Golf Club course in Juno Beach. Martin uses a red light which is invisible to turtles. (Photo by Greg Lovett/The Palm Beach Post)

Birds sit on the back of a zebra in the Nairobi National Park, near Nairobi, Kenya, November 21, 2018. (Photo by Baz Ratner/Reuters)

A man selling bags of water is seen at a taxi parking bay lined with campaign posters in the district of Lingwala in Kinshasa on December 18, 2018. Democratic Republic of Congo goes to the polls on December 23, 2018 in elections which could see the country emerge from 17 years of conflict-ridden rule under controversial President Joseph Kabila. (Photo by John Wessels/AFP Photo)

Triplet sisters Natalia, Irina and Tatiana Mironenko attend a rehearsal while preparing for examination performances staged by the graduates of the folk dance faculty of the Krasnoyarsk choreographic college in Krasnoyarsk, Russia May 13, 2019. All three 19-year-old sisters are expected to join the renowned Krasnoyarsk state academic dance ensemble of Siberia after the graduation. (Photo by Ilya Naymushin/Reuters)

A woman crosses a road outside the EU Parliament ahead of the EU elections in Brussels, Belgium, May 22, 2019. (Photo by Yves Herman/Reuters)

The trees on the iconic local landmark are silhouetted against glorious sunrise colours on a misty morning near Colmers Hill in Dorset, England on May 1, 2019. (Photo by Celia McMahon/Alamy Live News)

In this August 24, 2019 photo, a tractor pulls a trailer that was converted into a swimming pool as it drives along the roads of El Infernal neighborhood in San Andres in the province of Pinar del Río, Cuba. The idea for the mobile tractor-pool was hatched by local parents, to make their kids happy and fight the harsh Caribbean heat. (Photo by Ramon Espinosa/AP Photo)