A Chesterfield Borough Police telephone operator tests a gasmask with built in earpiece and microphone. The telephone service is considered one of the most important links in the coordination of ARP operations and must remain operational during air raids, 12th April 1939. (Photo by Fox Photos/Hulton Archive/Getty Images)
The Greyfriars Bobby statue is pictured wearing a mask as the spread of the coronavirus disease (COVID-19) continues, in Edinburgh, Scotland, Britain, March 23, 2020. (Photo by Russell Cheyne/Reuters)
Pigeons cool down at a public fountain on a hot summer day at University Plaza in downtown Bucharest, Romania, 10 June 2020. Temperatures in Bucharest reached 30 degrees Celsius. (Photo by Robert Ghement/EPA/EFE)
Afghan wrestlers compete in a bout of traditional mud wrestling competition during the Friday weekend at a field in Chaman-e- Huzuri ground in Kabul on October 21, 2022. (Photo by Wakil Kohsar/AFP Photo)
A group of volunteers dressed as elves and a man dressed as the grinch take part in a Christmas celebration organised by the NGO “Unos Venezolanos” in the neighbourhood of Petare, in Caracas, Venezuela on December 21, 2022. (Photo by Gaby Oraa/Reuters)
A WZ-10 attack helicopter performs during Airshow China 2022 at Zhuhai Air Show Center on November 9, 2022 in Zhuhai, Guangdong Province of China. The 14th Airshow China will be held from Nov. 8 to 13. (Photo by Qian Baihua/VCG via Getty Images)