A donkey savors warming temperatures after a long winter at the zoo in Warsaw, Poland, on Wednesday, April 8, 2015. (Photo by Czarek Sokolowski/AP Photo)

Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

Juanita Robinson (L) from Ohio and Trenaya Blackburn pose as Quan White from Michigan takes their picture as they vacation on South Beach on May 16, 2016 in Miami Beach, Florida. The Florida government announced it broke a tourism record in the first quarter of this year, attracting 29.8 million tourists, an increase of 4.8 percent over the same time frame in 2015. (Photo by Joe Raedle/AFP Photo)

A picture made available on 21 July 2016 shows a visitor having a meal from a toilet bowl at “Jamban Cafe” (lit. Toilet Cafe) in Semarang, Central Java, Indonesia, 16 July 2016. The cafe was created by a sanitation expert for education purposes to stress the importance of using a dedicated toilet and keeping it clean to prevent disease. (Photo by EPA/Purwanto)

A worker stack bricks on his head at a brick factory in Lalitpur January 12, 2015. (Photo by Navesh Chitrakar/Reuters)

The waning moon is setting over the mountain “Les Cornettes de Bise” located at the border of the Haute-Savoie and the Valais canton of Switzerland in the Chablais Alps, photographed from Glutieres, January 7, 2015. (Photo by Anthony Anex/EPA)

A picturesque supercell formation in the northwest of Booker, Texas from June 2013. (Photo by Mike Olbinski/Barcroft Media)

A participant runs in high-heels as she competes in the Stiletto Run in Bucharest June 14, 2014. The annual 50 metres race requires participants to wear high-heels that are at least 7cm tall. (Photo by Bogdan Cristel/Reuters)