Workers sleep on a railway track under repair in New Delhi, India, June 15, 2018. (Photo by Saumya Khandelwal/Reuters)

A competitor shouts as he takes part in the “Tough Guy” adventure race near Wolverhampton, central England, on January 29, 2017. The Tough Guy event, which is being held for the final time in its 30th year, challenges thousands of competitors to run a gruelling course whilst negotiating over 200 obstacles including: water, fire, and tunnels. (Photo by Oli Scarff/AFP Photo)

The "Skylanders Eruptor" balloon moves by people on balconies during the 89th Macy's Thanksgiving Day Parade in the Manhattan borough of New York, November 26, 2015. (Photo by Andrew Kelly/Reuters)

A member of the “Sibspas” Siberian search and rescue group dressed as Santa Claus (R), waits for his team mate, dressed as Father Frost, the Russian equivalent of Santa Claus, as he climbs the rock named “The Fourth Stolb” (the Fourth Pillar) at the Stolby national nature reserve during a training session of the Russian Emergencies Ministry, outside the Siberian city of Krasnoyarsk, Russia December 15, 2015. (Photo by Ilya Naymushin/Reuters)

South Korean workers are seen from a crane as they work on the 123rd floor during the framing completion ceremony of the 'Lotte World Tower' in Seoul, South Kora, 22 December 2015. The building's exterior was completed in a final height of 550 meters, and 123 floors. The ceremony came five years and two months after the construction of the building began and its opening will likely take place at the end of next year when the interior work is set to be completed, the South Korean Yonhap news agency reported. The building is the highest in South Korea and the fifth highest in the world, according to Yonhap. (Photo by Jeon Heon-Kyun/EPA)

Tourists feed freshly picked grapes to 40-year-old elephant Boonruen, a long-term resident of the Hua Hin Hills vineyard, that used to be an elephant corral in Hua Hin, about 200km southwest of Bangkok, Thailand, 08 March 2016. The winery is among a handful of companies producing new latitude wines in non-traditional wine areas of the world near the equator. Harvest is only once a year in Thailand, this year in March. (Photo by Barbara Walton/EPA)

A red fox sits in front of a Eurofighter Typhoon combat jet on the grounds of the 2014 ILA Berlin Air Show, in Selchow near Schoenefeld, Germany, Thursday, May 15, 2014. The International Aviation and Aerospace Exhibition ILA will take place from May 20 until May 25, 2014. (Photo by Patrick Pleul/AP Photo/DPA)

“Theyyam”. Preparation for the Theyyam performance in the surroundings of Kasaragod city. Theyyam is a popular ritual dance form of North Kerala, particularly in Kannur and Kasargod districts. The Theyyam represents a mythological, divine or heroic character. Make up of Theyyams is done by specialist. There are different types of face painting for which primarily and secondary colours are used. Therefore it is essential that the makeup man should have perfect knowledge of primary and secondary colour combinations. Sometimes, it takes several hours to paint each face. Photo location: Kasaragod, India. (Photo and caption by Rafal Ziejewski/National Geographic Photo Contest)