Ostriches wear masks as they are transported by a truck for relocation in Zhengzhou, Henan Province, China, August 8, 2016. (Photo by Reuters/Stringer)
People ride on a truck as they return to their families ahead of the Eid al-Adha festival in Khartoum September 11, 2016. (Photo by Mohamed Nureldin Abdallah/Reuters)
Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)
Racegoers during Ladies Day of the 2018 Cheltenham Festival in Cheltenham, England on March 14, 2018. (Photo by Graham Stone/Rex Features/Shutterstock)