Dan Copeland, left, and Alex Morneau of Biddeford, Maine, former high school cheerleaders, perform back flips while enjoying the record breaking heat, Thursday, May 18, 2017, at Old Orchard Beach, Maine. The temperature climbed well into the 90s in many locations throughout the state. (Photo by Robert F. Bukaty/AP Photo)

Horse riders perform with guns during the El-Jadida International Horse Show in El-Jadida, south of Casablanca, Morocco, October 15, 2016. (Photo by Youssef Boudlal/Reuters)

A man and a dog bathe in a fountain during celebrations of Paratroopers' Day in Moscow' s Gorky Park on August 2, 2017. Russia' s Airborne Troops (Blue Berets) celebrate their professional holiday on the Day of Elijah the Prophet, their Patron. (Photo by Stanislav Krasilnikov/TASS)

This image obtained January 31, 2017 from the US Geological Survey's Hawaiian Volcano Observatory showing a lava stream, pouring out of the lava tube on the sea cliff at the Kamokuna ocean entry from the Kilauea Volcano on January 29. (Photo by AFP Photo/USGS)

A participant prepares for the Red Bull Air Race World Championships in Abu Dhabi, United Arab Emirates on February 6, 2017. (Photo by Red Bull Content Pool/SIPA Press/Rex Features/Shutterstock)

A soldier of the French Foreign Legion holding his regiment's banner at Bar Hacheim in Libya, circa 1940. (Photo by Three Lions). P.S. All pictures are presented in high resolution.

A man poses as “Lemongrab” from Adventure Time outside the MCM Comic Con at the Excel Centre in East London, October 25, 2014. (Photo by Andrew Winning/Reuters)

A protestor makes a selfie in front of a burning car during a national trade union demonstration in Brussels, Thursday November 6, 2014. Tens of thousands of demonstrators are converging on the Belgian capital to protest government policies that will extend the pension age, contain wages and cut into public services. (Photo by Geert Vanden Wijngaert/AP Photo)