An elderly man uses a fan to shade himself from the sun as he walks in a public park in Beijing, Tuesday, June 7, 2016. Thursday marks the Duanwu Festival, a public holiday in China celebrated with outdoor activities including dragon boat races. (Photo by Mark Schiefelbein/AP Photo)

Firefighters of the Texas Canyon Hotshot crew fight the Sand Fire on July 23 2016 near Santa Clarita, California. Fueled by temperatures reaching about 108 degrees fahrenheit, the wildfire began yesterday has grown to 11,000 acres. (Photo by David McNew/AFP Photo)

Selfie picture shows Swiss pioneer Bertrand Piccard during the last leg of the round the world trip with Solar Impulse 2 over the Arab peninsula July 25, 2016. (Photo by Jean Revillard/Bertrand Piccard/Reuters/SI2)

A member of the Acorda Capoeira (Awaken Capoeira) group performs on a rooftop in the Rocinha favela in Rio de Janeiro, Brazil, July 24, 2016. In a favela with a history of violence between police and drug gangs, or armed battles between traffickers themselves, capoeira is an outlet that gives kids a sense of community – its practice a collective exercise blending characteristics of drum circles, sparring and tag-team gymnastics. (Photo by Bruno Kelly/Reuters)

A competitor takes part in the 31st World Bog Snorkelling Championships, held annually at Llanwrtyd Wells in Wales, Britain August 28, 2016. Entrants must negotiate two lengths of a 60-yard trench through the peat bog in the quickest possible time without using any conventional swimming strokes. (Photo by Rebecca Naden/Reuters)

In this May 2, 2015 photo, skywriter Nathan Hammond releases smoke as he writes messages of hope and love over New Orleans, during the New Orleans Jazz & Heritage Festival. Hammond was commissioned by local entrepreneur, Frank Scurlock, who said the messages were simply his way of reminding people that goodness can still flourish in a world that seems increasingly marred by violence. (Photo by Gerald Herbert/AP Photo)

A protester runs from a jet of water shot from a police water cannon in the courtyard of the University of Santiago, during clashes between students and police, in Santiago, Chile, Thursday, May 14, 2015. In the capital and other cities across the country, high school and university students marched, for the second time this year, to demand education reform. (Photo by Luis Hidalgo/AP Photo)

Kashmiri vegetable vendors assemble at a floating market in the interiors of the Dal Lake in Srinagar April 17, 2012. (Photo by Danish Ismail/Reuters)