An elderly man uses a fan to shade himself from the sun as he walks in a public park in Beijing, Tuesday, June 7, 2016. Thursday marks the Duanwu Festival, a public holiday in China celebrated with outdoor activities including dragon boat races. (Photo by Mark Schiefelbein/AP Photo)

A Poison Ivy and Boba Fet (Star Wars) cosplayer during the MCM Birmingham Comic Con at NEC Arena on March 18, 2017 in Birmingham, England. (Photo by Ollie Millington/Getty Images)

Residents with their empty containers crowd around a municipal tanker to fetch water in New Delhi, India, February 22, 2016. The Indian army has taken control of a canal that supplies three-fifths of Delhi's water, the state's chief minister said on Monday, raising hope that a water crisis in the metropolis of more than 20 million people can be averted. (Photo by Anindito Mukherjee/Reuters)

Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

A ring-tailed lemur is pictured at Zoom Torino, a zoological park in Cumiana near Turin, on April 22, 2015. Zoom Torino is a new immersive zoological park, where animals can be seen without bars or cages, only natural barriers ensure the visit. (Photo by Marco Bertorello/AFP Photo)

A Bengal tiger licks a glass enclosure during a presentation of Bengial tiger cubs at the Malabon Zoo in Malabon City, north of Manila, Philippines, 14 July 2016. The Bengal tiger cubs, which were born at the zoo, are two months old and named “Tiger Duterte” and “Tiger Leni”. The Malabon Zoo has one of the largest private collections of exotic and endemic animals in the Philippines. (Photo by Mark R. Cristino/EPA)

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)

A 19-year-old Japanese macaque monkey named Monday sneezes while suffering an allergy to pollen from the cedar tree, at Awajishima Monkey Center on March 26, 2012 in Sumoto, Hyogo, Japan. Some twenty monkeys are suffering the effects of hay fever at this time of the year, with the typical symptoms being the same as with humans. (Photo by Buddhika Weerasinghe/Getty Images)