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)

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)

Musician Jerome Gamble plays guitar to accompany the recorded music as it is played to the city below on September 01, 2020 in Bristol, England. Created by Bristol-based artist Luke Jerram and composer Dan Jones, “Sky Orchestra – A Moment in Time” was first performed at the Bristol International Balloon Fiesta in 2003. (Photo by Finnbarr Webster/Getty Images)

A waxworks artist retouches one of the wax figures at the unveiling of Little Mix waxwork figures at Madame Tussauds, in London, Britain, July 28, 2021. (Photo by Peter Nicholls/Reuters)

People cool off in Crown Fountain in Millennium Park on August 12, 2021 in Chicago, Illinois. As temperatures climb across the nation, nearly 200 million Americans are under some level of heat advisory. (Photo by Scott Olson/Getty Images)

A Palestinian man sells corn at Gaza Beach during sunset on August 8, 2021. (Photo by Sameh Rahmi/NurPhoto/Rex Features/Shutterstock)

A diver swims near sculptures during the inauguration of the underwater museum in Ayia Napa, Cyprus, 01 August 2021. At the new Ayia Napa Underwater Sculpture Museum (MUSAN), located in the Pernera area of Ayia Napa, visitors, both swimmers with mask and flippers and divers, will be able to tour around an underwater forest, the first of its kind in the world. (Photo by Jason Decaires Taylor/EPA/EFE)

Flt Lt James Sainty flew a Typhoon in the final air show of the season at Duxford in Cambridgeshire in September 2021. (Photo by Claire Hartley/Bav Media)