A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

A woman whose livelihood depends on selling recyclable wastes collects trash from a dumping site while surrounded by Marabou storks on the outskirts of Uganda's capital Kampala March 31, 2015. (Photo by James Akena/Reuters)

Members of the Gafatar sect walk in the rain as they evacuate their compound, which was later burned down by local villagers, in Antibar village, Mempawah Regency, Indonesia West Kalimantan Province, January 19, 2016 in this photo taken by Antara Foto. Local authorities and police moved the sect members to an army barracks located some 70 km (43 miles) away from Antibar for their safety following recent disputes between the sect and the villagers, Antara said on Tuesday. (Photo by Jessica Helena Wuysang/Reuters/Antara Foto)

A Thai villager runs with a bullock during a catching a bullock competition as part of the annual bullock cart racing festival in Phetchaburi province, Thailand, 21 February 2016. The annual bullock cart race festival held to celebrate the end of the harvest season. (Photo by Rungroj Yongrit/EPA)

People cross the street in central Pyongyang, North Korea May 4, 2016. (Photo by Damir Sagolj/Reuters)

Street musicians with their faces covered with animal masks play to earn some money in central Vienna, Austria, November 8, 2015. (Photo by Vasily Fedosenko/Reuters)

People on motor bikes celebrate American President Barack Obama's visit to Kenya by holding up a photo, center top, of the president and First Lady Michelle Obama in Kisumu, Kenya, Saturday, July 25, 2015. President Barack Obama heralded Africa as a continent “on the move” Saturday as he opened a U.S.-sponsored business summit in Kenya, the East African nation where he has deep family ties. (Photo by AP Photo)

Aerobatic pilot Sean D. Tucker flies in the two-seat Oracle Extra airplane over downtown Chicago skyline, Wednesday, June 8, 2016. Tucker will perform before the start of of the America's Cup World Series racing on Saturday and Sunday. (Photo by Kiichiro Sato/AP Photo)