Men cover their heads from the sun while riding on a motorcycle during a hot day in Cairo, Egypt, August 17, 2015. A heatwave killed at least 61 people across Egypt from Sunday to Tuesday and caused nearly 600 people to be admitted to hospital, Egypt's health ministry said on state news agency MENA on Wednesday. (Photo by Amr Abdallah Dalsh/Reuters)

A man walks his dog as the sun sets in a park in Frankfurt, Germany, Monday, September 18, 2017. Cool damp weather is set to continue in this part of Germany for the next few days with temperatures in the mid teens Celsius. (Photo by Michael Probst/AP Photo)

A young girl takes selfie with Easter rabbit sculpture during the Easter eggs (Pysanka) and rabbit exhibition in front of St. Sophia Cathedral in Kiev, Ukraine, 05 April 2018. Ukrainians will mark Orthodox Easter on 08 April 2018, according to Julian calendar. (Photo by Sergey Dolzhenko/EPA/EFE/Rex Features/Shutterstock)

Nutrias venture near the camera at the river Nidda in Frankfurt am Main, Germany, 15 June 2017. The rabbit sized animals are often confused with biebers by amateurs. (Photo by Boris Roessler/DPA)

A visitor takes in a view of the downtown district from Twin Peaks on Friday, January 9, 2015, in San Francisco. (Photo by Marcio Jose Sanchez/AP Photo)

Handout photo dated March 20, 2015 issued by Chester Zoo of lemurs looking at the eclipse over Chester Zoo. (Photo by Steve Rawlins/PA Wire/Chester Zoo)

“Don't Leave Any Food On Your Plate”. The giraffes at Nairobi's Giraffe Manor are totally at home with humans. They will eat out of your hand, or even off your plate. Photo location: Giraffe Manor, Nairobi, Kenya. (Photo and caption by Gavin Werbeloff/National Geographic Photo Contest)

Sri Lankan participants control their bulls during a traditional cart race to mark the Sri Lanka National New Year in Homagama near Colombo on April 23, 2017. The new year marked by both the majority Sinhalese and minority Tamil population fell on April 14. (Photo by Lakruwan Wanniarachchi/AFP Photo)