An Indian girl smiles under a water splash at a water park as the temperatures reached 38 degree Celsius in Calcutta, eastern India, 12 June 2016. The summer or pre-monsoon season lasts from March to July in eastern India with the highest day temperatures ranging from 38 to 45 degrees Celsius. (Photo by Piyal Adhikary/EPA)

Jean-Pierre Giagnoli walks through a crowded area of vendors hawking cat related goods at CatCon LA in Los Angeles, on Sunday, June 26, 2016. (Photo by Richard Vogel/AP Photo)

Women pose for a selfie at Ipanema Beach in Rio de Janeiro, Brazil on July 30, 2016. (Photo by Nacho Doce/Reuters)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)

World medieval jousting champion Rod Walker poses before next month’s St Ives Medieval Faire, the only solid wood lance joust tournament in the southern hemisphere in Sydney, Australia on August 26, 2016. (Photo by Dan Himbrechts/AAP)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

The villas of Marabe Al Dhafra in Abu Dhabi, United Arab Emirates are home to approximately 2,000 people. Located in one of the hottest regions of the world, the record high temperature here is 49.2C° (120.6F°). (Photo by Benjamin Grant/Penguin Random House)

A youth in make-up waits for the start of the annual Zombie walk in Mexico City, Saturday, October 22, 2016. Hundreds dressed in rags and ghoulish makeup to look bloody and decaying, gathered in the historic center of Mexico's capital. (Photo by Christian Palma/AP Photo)