Men cover their heads from the sun while riding on a motorcycle during a hot day in Cairo, Egypt, August 17, 2015. A heatwave killed at least 61 people across Egypt from Sunday to Tuesday and caused nearly 600 people to be admitted to hospital, Egypt's health ministry said on state news agency MENA on Wednesday. (Photo by Amr Abdallah Dalsh/Reuters)

A Syrian migrant family enters Hungary at the border with Serbia near Roszke, Hungary August 28, 2015. As Europe struggles with its worst migrant crisis since World War II, Hungary has become, like Italy and Greece, a “frontline” state. So far this year, police say around 141,500 migrants have been intercepted crossing into Hungary, mostly from neighbouring Serbia. (Photo by Bernadett Szabo/Reuters)

Marco Antonio Eguchi of Brazil gets bucked off of Bottoms Up in the first round of the PBR Frontier Communications Iron Cowboy at AT& T Stadium on February 18, 2017 in Arlington, Texas. (Photo by Tom Pennington/Getty Images)

“7584 Fish”. On a windy day right after a Cyclone passed the far northern Great Barrier Reef i took some friends out to the reef. Never before i saw that many glass fish on this particular coral “bommie”. Just when i setup my camera, this Napoleon Wrasse swam right through the school of fish building a living frame. Photo location: Cairns, Great Barrier Reef, Flynn Reef, Australia. (Photo and caption by Christian Miller/National Geographic Photo Contest)

Animal rights activists covered with fake blood sit on the floor during a protest against the use of animals in research to mark World Day for Animals in Laboratories in central Madrid April 24, 2014. The sign reads, “How many rabbits do your shampoo kill?”. (Photo by Andrea Comas/Reuters)

A workman smooths out the gravel near the base of British artist Alex Chinneck' latest sculpture “A bullet from a shooting star” on the Greenwich Peninsula in London on September 17, 2015. The 35-metre tall, upside-down electricity pylon overlooks the Canary Wharf financial district. (Photo by Leon Neal/AFP Photo)

Playboy Bunnies pose for a selfie at the premiere of “The Transporter Refueled” at Playboy Mansion in Los Angeles, California August 25, 2015. The movie opens in the U.S. on September 4. (Photo by Mario Anzuoni/Reuters)

“People and Space”. Winner: Wanderer in Patagonia by Yuri Zvezdny (Russia) A lone stargazer stares up at the stars of our galaxy, the Milky Way, as they stretch across the night sky over the glacier “White Stones” (Piedras Blancas) in the Los Glaciares National Park, Argentina. El Chaltén, Santa Cruz Province, Argentina, 27 September 2016 iOptron Sky-Tracker mount, Sony A7S camera, 18 mm f/2.8 lens, ISO 5000, 30-second exposure Wanderer in Patagonia. (Photo by Yuri Zvezdny/Insight Astronomy Photographer of the Year 2017)