A masked reveller parades through the streets on the first day of the carnival season in Lucerne, Switzerland, 12 February 2015. In the background the well known Kappellbruecke bridge. (Photo by Alexandra Wey/EPA)

This picture taken on January 25, 2015 shows a participant taking part in an ice water challenge in Zhangjiajie, central China's Hunan province. Participants were required to stay in an ice pond, holding an ice block while eating ice-cream with an electric fan blowing at them. (Photo by AFP Photo/Stringer)

Al-Shamiyah Front fighters inspect a new locally-made cannon named “Borkan” (Volcano) as it was being launched towards forces loyal to Syria's president Bashar Al-Assad located in Aleppo artillery school, March 7, 2015. The “Borkan” is made out of four tubes attached to a loader, which can fire four shells at a time, and have a range of three kilometers (1.86 miles). (Photo by Abdalrhman Ismail/Reuters)

Actress Kerry Washington, Harvard University's Hasty Pudding Theatricals' Woman of the Year, throws wine in the face of an actor playing Republican presidential candidate Donald Trump, Thursday, January 28, 2016, as she is roasted in Cambridge, Mass. (Photo by Elise Amendola/AP Photo)

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)

Local residents crowd a swimming pool during a hot weather in Suining, Sichuan province, 27 July 2008. (Photo by Reuters/Stringer)

The rarely seen blue sharks photographed by Saeed Rashid in British waters. Elusive blue sharks have recently been spotted off the south coast of England, having moved to the UKs warmer waters to hunt. The carnivorous sharks have been lurking off the coast of the popular British holiday destination, Penzance, in Cornwall. (Photo by Saeed Rashid/Caters News)

In this photograph taken on October 4, 2016, an Afghan baker prepares bread at his shop as he waits for customers in Lashkar Gah, the capital city of Helmand province. For years Helmand was the centerpiece of the Western military intervention in Afghanistan only for it to slip deeper into a quagmire of instability, with almost the entire southern province teetering on the verge of collapse. Intensified fighting has killed hundreds and forced thousands to flee to besieged capital Lashkar Gah, sparking a humanitarian crisis as the city – one of the last government- held enclaves – risks falling to the Taliban' s repeated ferocious assaults. (Photo by Wakil Kohsar/AFP Photo)