A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

Girls watch a procession during the “Fiesta de las Palancas” celebration to ask for blessings and abundance during the new year in Panchimalco, El Salvador, January 5, 2017. (Photo by Jose Cabezas/Reuters)

A garbage collector, with his horse and cart, prepares to unload rubbish at the municipal dump in Nezahualcoyotl, on the outskirts of Mexico City, February 18, 2015. Hundreds of horse or donkey-drawn carts will disappear from the streets of a municipality in the state of Mexico, located on the outskirts of Mexico City, and will be replaced by motorized vehicles, local authorities said. (Photo by Henry Romero/Reuters)

A woman reacts while walking among the ruins of damaged buildings following heavy fighting between government troops and Kurdish fighters, on March 2, 2016 in the southeastern Turkey Kurdish town of Cizre, near the border with Syria and Iraq. Thousands in Turkey's Kurdish-majority town of Cizre started returning to their homes today after authorities partially lifted a curfew in place since December for a controversial military operation to root out separatist rebels. (Photo by Yasin Akgül/AFP Photo)

A Thai mahout and his elephant, both dressed as Santa Claus pass in font of a large photograph of Thai King Bhumibol Adulyadej following a Christmas event at a school in the world heritage city of Ayutthaya, north of Bangkok, Thailand, 24 December 2015. The annual event is held to celebrate the Christmas season in the overwhelmingly Buddhist kingdom. (Photo by Diego Azubel/EPA)

A high temperature alerts were issued as a record-setting summer heat wave continued to bake most parts of south China. (Reuters)

A man takes pictures at the finish line during the Colour Run at Centennial Park in Sydney August 25, 2013. According to organizers, 15,000 runners registered to complete the 5km (3 miles) course in Centennial Park on Sunday, being covered in blue, pink, orange and yellow powder on their way to the finish line. (Photo by Daniel Munoz/Reuters)

A woman poses as she has her picture taken amid 1600 panda bear sculptures in Berlin August 5, 2013. Marking the 50th anniversary of its existence, on Monday the German branch of the World Wide Fund for Nature (WWF) environmental conservation organisation placed 1600 panda bear sculptures on front of Berlin's main train station to draw attention to the plight of the endangered species that serves as the NGO's mascot. There are currently 1600 panda bears alive in the wild, the organisation said in a press release. (Photo by Thomas Peter/Reuters)