Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

In this Thursday, March 17, 2016 photo, 33-year-old Palestinian clown doctor Alaa Miqdad, left, entertains 3-year-old patient Yaqin Shawaf, who suffers from dialysis, in the department of kidney diseases at Al-Rantisi children's hospital in Gaza City. (Photo by Adel Hana/AP Photo)

Bathers brave the cold waters of the North Sea as they take part in the annual Boxing Day dip at Redcar Beach on December 26, 2019 in Redcar, England. The event attracts hundreds of people each year who take to the cold water wearing fancy dress as they help to raise money for a number of charities. (Photo by James Glossop/The Times)

Japan's Naomi Osaka sits with her towel over her head during a break in her third round loss to Coco Gauff of the U.S. at the Australian Open tennis championship in Melbourne, Australia, Friday, January 24, 2020. (Photo by Lee Jin-man/AP Photo)

People wearing masks and carrying supplies walk past a mannequin wearing a mask in downtown Barcelona, Spain, Saturday, March 14, 2020. Spain's prime minister has announced a two-week state of emergency from Saturday in a bid to contain the new coronavirus outbreak. For most people, the new coronavirus causes only mild or moderate symptoms. For some, it can cause more severe illness, especially in older adults and people with existing health problems. (Photo by Emilio Morenatti/AP Photo)

Rajesh Babu, a police officer, wearing a helmet depicting coronavirus, requests a commuter to stay at home during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19), in Chennai, India, March 28, 2020. (Photo by P. Ravikumar/Reuters)

A member of the contemporary circus company Cirk La Putyka perform on the mobile trampoline as he amuses local residents in Prague, Czech Republic, 09 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)

People get covered with powdered colors to celebrate the Holi festival in Bangalore, India on March 21, 2019. Holi is observed at the end of the winter season on the last full moon day of the lunar month Phalguna, which usually falls in the later part of February or March. (Photo by Jagadeesh N.V./EPA/EFE/Rex Features/Shutterstock)