People cool off in a fountain outside the Southbank Centre on June 30, 2015 in London, England. The UK is currently experiencing a heatwave, with temperatures of 35 degree celsius forecast tomorrow in some parts of the country. The extreme heat has already seen train cancellations and a health warning has been issued. (Photo by Rob Stothard/Getty Images)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

Members of the contemporary circus company Cirk La Putyka perform in front of sculpture of Franz Kafka's head to entertain local residents in Prague, Czech Republic, 21 April 2020. The aim of the Cirk La Putyka events in the streets of Czech capital is to get live art back to people during the lockdown. According to them, when people can't go to the artists, to the theater, the actors go to the people. The Czech government has imposed a lockdown in an attempt to slow down the spread of the pandemic COVID-19 disease caused by the SARS-CoV-2 coronavirus. (Photo by Martin Divisek/EPA/EFE/Rex Features/Shutterstock)

Rummaging in a bin for scraps, this fox in Barnet, north London, England found itself trapped in the lid on May 23, 2019. Luckily the Royal Society for the Prevention of Cruelty to Animals were able to free it. (Photo by RSPCA/PA Wire Press Association)

A robin perches on a spade handle in a garden on a rainy day in Lixwm, north Wales. Researchers said this week that when European robins are subjected to human-produced noise, their behaviour changes. (Photo by DGDImages/Alamy Live News)

A man runs on a small road in the outskirts of Frankfurt, Germany, before sunrise on Tuesday, September 1, 2020. (Photo by Michael Probst/AP Photo)

A migrant worker wearing face masks to help curb the spread of the coronavirus walks up to a pedestrian bridge in Beijing, Sunday, December 6, 2020. Provincial governments across China are placing orders for experimental, domestically made coronavirus vaccines, though health officials have yet to say how well they work or how they may reach the country's 1.4 billion people. (Photo by Andy Wong/AP Photo)

A robot, developed by start-up firm Asimov Robotics, holds a tray with face masks and sanitizer after the two robots were launched to spread awareness about the coronavirus, in Kochi, India, March 17, 2020. (Photo by Sivaram V/Reuters)