A man rides a bicycle by a graffiti under the “Old Sava bridge” over Sava river in Belgrade, Serbia, Wednesday, May 19, 2021. (Photo by Darko Vojinovic/AP Photo)

A young girl splashes through a waterfall at a park in Washington, DC, on June 28, 2021, as a heatwave moves over much of the United States. Swathes of the United States and Canada endured record-setting heat on June 27, 2021, forcing schools and Covid-19 testing centers to close and the postponement of an Olympic athletics qualifying event, with forecasters warning of worse to come. The village of Lytton in British Columbia broke the record for Canada's all-time high, with a temperature of 46.6 degrees Celsius (116 Fahrenheit), said Environment Canada. (Photo by Jim Watson/AFP Photo)

A resident reacts as a health worker collects a swab sample to test for the Covid-19 coronavirus in Colombo on July 27, 2021. (Photo by Ishara S. Kodikara/AFP Photo)

People enjoying the second day of the Greenman Festival in South Wales, Crickhowell, United Kingdom on August 20, 2021. (Photo by Chris Fairweather/Huw Evans/Rex Features/Shutterstock)

A cheerleaders team member wearing a pseudo anti-coronavirus face mask performs during the St. Petersburg Open ATP tennis tournament match in St.Petersburg, Russia, Wednesday, October 27, 2021. (Photo by Dmitry Lovetsky/AP Photo)

Giant panda Shuixiu's two babies are pictured at their room in Shenshuping base of China Conservation and Research Center for the Giant Panda on November 3, 2021 in Aba Tibetan and Qiang Autonomous Prefecture, Sichuan Province of China. (Photo by An Yuan/China News Service via Getty Images)

Glam revellers have proudly shown off their vaccine passports as they glammed up for a night on the town on the first day of fresh Covid restrictions in Newcastle, United Kingdom on December 15, 2021. Brits donning festive gear decided to tear up nightclub dance floors and booze in pubs despite fears over the Omicron variant. (Photo by Newcastle New Projects)

A young patient with relatives watches through a window as a Russian emergency rescue student dressed as Snegurochka (Snow Maiden) perform, outside the Morozov Children's City Clinical Hospital marking the upcoming New Year and Christmas celebrations in Moscow, Russia, Sunday, December 19, 2021. (Photo by Alexander Zemlianichenko Jr./AP Photo)