Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

This Wednesday, August 31, 2016 photo, provided by the Syrian anti-government activist group Aleppo Media Center (AMC), shows Syrian boys dive into a hole filled with water that was caused by a missile attack in the rebel-held neighborhood of Sheikh Saeed in Aleppo province, Syria. (Photo by Aleppo Media Center via AP Photo)

A roadside currency exchange vendor sorts Indian currency notes at his stall in Agartala, India, December 6, 2016. (Photo by Jayanta Dey/Reuters)

Kashmiri residents are evacuated in a tractor from their flooded neighborhood in Srinagar, India, Sunday, September 7, 2014. (Photo by Dar Yasin/AP Photo)

Zhao Qiang walks across a street in Shenyang, Liaoning province, April 14, 2014. Zhao, a community officer of the China Disabled Persons' Federation, was diagnosed with multiple when he was two, with the resulting tumour affecting the growth of his left leg, his grandmother told local media, citing a doctor's diagnosis. His uncle modified his shoes, fitting them with stools, to allow Zhao to stand and walk. (Photo by Reuters/Stringer)

Iraqi paramilitary troops fire towards Islamic State militants during a battle with Islamic State militants on the outskirts of the ancient city of Hatra near Mosul,Iraq April 26, 2017. (Photo by Reuters/Stringer)

People stand in front of a black ribbon, symbolising remembrance and mourning, being projected onto the Sydney Opera House on February 9, 2023 in solidarity with Turkey and Syria after a massive earthquake devastated the two countries. (Photo by David Gray/AFP Photo)

A person carries a fan in Westminster, London, Britain, 12 July 2022. Britain has been issued with an amber weather warning for the weekend as experts predict that temperatures could rise to the high thirties and Sunday could be the hottest day on record for the UK. (Photo by Tolga Akmen/EPA/EFE/Rex Features/Shutterstock)