A competitor participates in the Tough Mudder challenge near Henley-on-Thames in southern England May 2, 2015. (Photo by Eddie Keogh/Reuters)

A helicopter drops water over a wildfire as a firefighter works to contain it in Benahavis, southern Spain, May 19, 2015. (Photo by Jon Nazca/Reuters)

A man pours water on his camel on a hot summer day in Ahmedabad, India, May 18, 2017. (Photo by Amit Dave/Reuters)

A mahout bathes his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India May 21, 2017. (Photo by Amit Dave/Reuters)

A makeup artist works on a model during the Tunis Fashion Week 2018 in Tunis, Tunisia, 12 May 2018. (Photo by Mohamed Messara/EPA/EFE)

A man sleeps at Beirut's Corniche, a seaside promenade, in Lebanon May 2, 2016. (Photo by Alia Haju/Reuters)

A mannequin stands in a textile factory in Madrid, Spain May 19, 2014. (Photo by Andrea Comas/Reuters)

Model present creations by Emilia Wickstead for Matchesfashion.com during Australian Fashion Week, May 15, 2018. (Photo by Edgar Su/Reuters)