Wang Zhengqing, a 74 year old pneumoconiosis patient, smokes his pipe at Yangjia Hospital in Wuyi County, Zhejiang Province, China October 19, 2015. Former miner Wang was diagnosed with the disease, which is caused by dust inhalation, when he was 24 and has lived at Yangjia Hospital for ten years. (Photo by Damir Sagolj/Reuters)

A demonstrator dressed as Santa Claus holds up a flag as a riot police vehicle releases a jet of water during a protest against the private system of pension fund administrators in Santiago, Chile, December 10, 2015. The flag reads “Classist Workers Union”. (Photo by Ivan Alvarado/Reuters)

A woman takes a dip in a font on the eve of the Orthodox Epiphany in central Moscow, Russia, January 18, 2016. Orthodox believers mark Epiphany on January 19 by immersing themselves in icy waters regardless of the weather. (Photo by Sergei Karpukhin/Reuters)

A refugee sits in front of a Greek riot police cordon during a protest at the Greek-Macedonian border, near the Greek village of Idomeni, March 1, 2016. (Photo by Alexandros Avramidis/Reuters)

Model, skydiver and wing-suit jumper Roberta Mancino, 33, swims with a whale shark on February 2014 in Isla Mujeres, Mexico. A female skydiver swims with whale sharks, manta rays and sailfish – the fastest fish in the sea. Model, skydiver and wing-suit jumper Roberta Mancino, 33, jumped from a boat into the ocean surrounding Isla Mujeres near the northern Peninsula of Mexico. The incredible project involved two trips to the stormy winter seas – one in February 2013 and one a year later in February 2014. (Photo by Shawn Heinrichs/Barcroft Media)

A passenger waits after his train arrived in Nouadhibou, Mauritania’s second largest city and the main export port for the country’s iron ore industry, on June 25, 2014. The mining company’s employees proudly call their firm the lung of their nation's economy and the train that ferries the ore to the coast stretches some two kilometres, making it one of the world's longest. SNIM mines black iron ore in the northern town of Zouerate, a remote desert location which nevertheless attracts people from all over the country looking for work. (Photo by Joe Penney/Reuters)

F/A-18 fighter jet takes off from the USS Harry S. Truman aircraft carrier in the eastern Mediterranean Sea June 13, 2016. (Photo by Baz Ratner/Reuters)

Revellers attend the Play Time 2016 music festival on the outskirts of Ulaanbaatar, Mongolia, June 26, 2016. (Photo by Jason Lee/Reuters)