Adventurer Sam Cossman movies towards the huge lava lake wearing a custom built industrial proximity heat suit on December 20, 2014 in Ambrym, Vanuatu. (Photo by Conor Toumarkine/Barcroft Media)

A man talks on his mobile phone in the village of Devmali in the desert state of Rajasthan, India June 14, 2016. (Photo by Himanshu Sharma/Reuters)

A fuel cell electric vehicle (FCEV) by Nissan is shown at China (Guangzhou) International Automobile Exhibition in Guangzhou, China November 18, 2016. (Photo by Bobby Yip/Reuters)

Supporters of the United Democratic Party (UDP) opposition alliance presidential candidate, Adama Barrow attend a campaign rally in Buffer zone, Gambia November 29, 2016. (Photo by Thierry Gouegnon/Reuters)

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

Wolfgang (L), member of World War One historical association “Darstellungsgruppe Suddeutsches Militar 1870-1918” (DSM 18), from Munich, Germany, and Florent, member of French association “Le Poilu de la Marne”, dressed in vintage army uniforms, visit the Bezonvaux bunker in the national forest of Verdun, eastern France, March 29, 2014. Members of French and German historical associations, who gather annually, together visited the battlefield of Verdun in France, the site of a bloody World War One battle that dragged on for around 10 months in 1916, claiming hundreds of thousands of lives and destroying many villages. (Photo by Charles Platiau/Reuters)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

A spring breaker takes a shot of tequila during a pool party at a hotel in Cancun March 8, 2015. Like previous Florida spring break hot spots Fort Lauderdale and Daytona Beach, Panama City Beach is facing a crisis of conscience over the trade-offs involved in hosting a binge for some 300,000 students who arrive through mid-April with coolers, beer funnels and credit cards. (Photo by Michael Spooneybarger/Reuters)