Vaccinators wear protective masks as they get their temperature checked, during an anti-polio campaign, in a low-income neighborhood as the spread of the coronavirus disease (COVID-19) continues, in Karachi, Pakistan on July 20, 2020. (Photo by Akhtar Soomro/Reuters)

English singer and songwriter Anne-Marie performs on stage during day two of Capital's Jingle Bell Ball with Seat at London's O2 Arena on December 8, 2019. (Photo by Isabel Infantes/PA Images via Getty Images)

Actress and model Rosie Huntington-Whiteley during an evening out and about in London, England on January 23, 2020. (Photo by Stephen Coke/Rex Features/Shutterstock)

Actresses from left Jurnee Smollett-Bell, Rosie Perez, Mary Elizabeth Winstead, Margot Robbie and Ella Jay Basco pose for a selfie photo upon arrival at the world premiere of “Birds of Prey” in London, Wednesday, January 29, 2020. (Photo by Joel C. Ryan/Invision/AP Photo)

Visitors are seen with giraffes on a bus at Safari Park in Kanchanaburi Province, Thailand, January 19, 2020. Kanchanaburi in western Thailand an area known for its waterfalls and caves. (Photo by Rachen Sageamsak/Xinhua News Agency/Eyevine)

British actress Laila Rouass poses during a studio shoot ahead of the new series of “Footballers Wives” at a London studio on January 28, 2004 in London. Rouass plays Conrad's bisexual wife Amber, and the nine-part series begins on ITV1 on February 11, 2004. (Photo by Stephen Perry/Getty Images)

The moon illuminates the snow-covered Concordia, the confluence of the Baltoro and Godwin-Austen glaciers, near the world's second highest mountain the K2 (8,000 meters) in the Karakoram mountain range in Pakistan September 6, 2014. While other parts of Pakistan and northern India were flooded, Concordia in the Karakoram mountain range was covered with a seasonally unusual amount of snow. Geographically, Pakistan is a climbers paradise. It rivals Nepal for the number of peaks over 7,000 meters and is home to the world's second tallest mountain, K2, as well as four of the world's 14 summits higher than 8,000 meters. (Photo by Wolfgang Rattay/Reuters)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)