A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

John Pfaff lays on a fallen tree Thursday, September 10, 2020, in Salt Lake City. Two days after a windstorm wreaked havoc in Utah, many schools remain closed and tens of thousands are still without power. (Photo by Rick Bowmer/AP Photo)

Two costumed reveler seen at the City center where normally thousands of revelers dressed in carnival costumes would celebrate the Rose Monday parade on the streets in Mainz, Germany, 15 February 2021. The Rose Monday Parade has been cancelled due to the coronavirus Covid-19 pandemic. (Photo by Ronald Wittek/EPA/EFE)

A competitor poses before the Tough Guy Challenge endurance race on January 27, 2013 in Telford, England. Every year thousands of people run the 8 mile assault course which involves freezing temperatures, fire and ice. (Photo by Michael Regan)

A woman react inside a cloud of paint powder during the holi one colour Festival held in the city of Cape Town, South Africa, Saturday, March 2, 2013. Thousands of people are taking part in the festival by throwing coloured paint powder at each other to express freedom and the colour of everyday life. (Photo by Schalk van Zuydam/AP Photo)

A Pakistani scavenger girl writes on a notebook she collected from a garbage, while another girl sits next to her in Lahore, Pakistan, Wednesday, April 1, 2015. Thousands of children pick recyclable items from waste dumping points to earn living for their poor families. (Photo by K. M. Chaudary/AP Photo)

Revelers, covered in coloured powder, celebrate, during a Holi Run Festival in Madrid, Spain, Sunday, April 12, 2015. Thousands of revelers took part in the festival that includes a mini marathon. The festivals are fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east of India. (Photo by Andres Kudacki/AP Photo)

Indian Muslim devotees travel in an auto rickshaw during the Urs festival in Ajmer, India, Thursday, April 23, 2015. Thousands of devotees from different parts of India travel to the shrine of Sufi saint Khwaja Moinuddin Chisht for the annual festival marking the saint's death anniversary. (Photo by Deepak Sharma/AP Photo)