A helicopter is silhouetted by glowing embers as it makes a water drop at the “Old Fire”, which burned in Calabasas, California, U.S., June 4, 2016. (Photo by Gene Blevins/Reuters)

A girl reacts as she receives polio vaccine drops during a house-to-house vaccination campaign in Yemen's capital Sanaa, November 10, 2015. (Photo by Khaled Abdullah/Reuters)

Photographer John Fatkin captured these jaw-dropping images of a rainbow and ferry on the River Tyne, England, with the iconic red-painted Herd Groyne Lighthouse. (Photo by Tom Fatkin/Cover Images)

A Thai drug user mixes the popular cheap narcotic drink as it is cooked over a fire on September 1, 2011 in Narwathiwat, southern Thailand. (Photo by Paula Bronstein/Getty Images)

Young girls carry containers filled with drinking water beside the railway station in Agartala, India, April 20, 2016. (Photo by Jayanta Dey/Reuters)

A man drinks at a "colored" water cooler in a streetcar terminal in Oklahoma City, July 1939. (Photo by Reuters/Library of Congress)

In this photo taken on Sunday, January 14, 2018, Anastasia Gruzdeva, left, poses for selfie with her friends as the temperature dropped to about –50 degrees (–58 degrees Fahrenheit) in Yakutsk, Russia. Temperatures in the remote, diamond-rich Russian region of Yakutia have dropped to near-record lows, plunging to –67 degrees Centigrade (-88.6 degrees Fahrenheit) in some areas. (Photo by Sakhalife.ru Photo via AP Photo)

The buildings of the banking district are seen through thousands of rain drops on a glass railing in central Frankfurt, Germany, Wednesday, January 11, 2017. (Photo by Michael Probst/AP Photo)