The head of a decapitated rooster is pictured after a rooster run, during celebrations in honour of San Juan Bautista in San Juan de Oriente town, Nicaragua, June 26, 2015. The rooster runs, where horse-riders try to pull the head off live roosters, symbolize the beheading of John the Baptist. (Photo by Oswaldo Rivas/Reuters)

People cool off in a fountain outside the Southbank Centre on June 30, 2015 in London, England. The UK is currently experiencing a heatwave, with temperatures of 35 degree celsius forecast tomorrow in some parts of the country. The extreme heat has already seen train cancellations and a health warning has been issued. (Photo by Rob Stothard/Getty Images)

The Solar Impulse 2 airplane, flown by test pilot Markus Scherdel, flies off the coast of Oahu during a test flight from Kalaealoa Airfield in Kapolei, Hawaii, March 3, 2016. The solar-powered plane is ready to continue its revolutionary voyage around the world. After the craft was grounded in Hawaii last July due to overheated batteries, it was repaired and upgraded, and a recent initial test flight proved successful. (Photo by Eugene Tanner/Reuters)

UFC women's bantamweight champion Holly Holm and Miesha Tate face off during the UFC 196 weigh ins at the MGM Grand Garden Arena in Las Vegas on Friday, March 4, 2016. (Photo by L.E. Baskow/Las Vegas Sun via AP Photo)

Sydney resident Virginia Maddock watches the supermoon rise off the Sydney beachside suburb of Wanda, August 10, 2014. Sunday’s moon was at its closest approach to Earth, appearing bigger and brighter than any other moon this year. The moon was 221,765 miles away and looked 16 percent larger and 30 percent brighter than usual. (Photo by Jason Reed/Reuters)

Hot lava trickles down from the Stromboli volcano on August 9, 2014 in Aeolian Islands, Italy. Lava flows down the Mount Stromboli off the Sicilian coast in southern Italy. The volcano – at 3,034ft – is one of the most active in Europe and has been erupting continuously since 1932. (Photo by Tom Pfeiffer/Barcroft Media)

From the rocks of Arnhem Land to the backyards of the Sydney suburbs, from stretching by the pool to waiting for evening prayer, snapshots for the 2015 Australian Life prize demonstrated a nation in colour and motion. Here: Children Cooling Off at Dhiari Homeland. Local children get wet and cool in Arnhem Land. (Photo by Matthew Abbott/Australian Life Prize 2015)

Members of the New Forest Hunt ride off from Boltons Bench for the annual Boxing Day hunt in Lyndhurst, southern England, Britain December 26, 2016. Since a ban stopped fox hunting with hounds, hunts continued with dogs chasing down a pre-laid scented trail instead of a fox. (Photo by Luke MacGregor/Reuters)