San Diego Ballet School students wear protective masks backstage during a performance of “The Nutcracker”, presented by the San Diego Ballet in a drive-in performance at a parking lot in San Diego, California, December 5, 2020. (Photo by Bing Guan/Reuters)

Workers wearing face masks as a protection against the coronavirus disease (COVID-19) carry roasted pigs, locally known as “lechon”, at a restaurant, in Quezon City, Metro Manila, Philippines, December 21, 2020. (Photo by Lisa Marie David/Reuters)

A woman wearing a protective mask walks outside a village that was placed under lockdown due to the number of COVID-19 cases among residents in Manila, Philippines on Thursday, March 11, 2021. The Philippine capital placed two villages and two hotels on lockdown Thursday and police have renewed warnings against kissing and other “public display of affection” after a new surge in coronavirus infections. (Photo by Aaron Favila/AP Photo)

Indonesian soldiers wearing facemasks and personal protective equipment take a part in a sack race during games to celebrate ahead of the country's 75th Independence Day in Surabaya, East Java on August 14, 2020. Indonesia will mark its 75th Independence Day on August 17. (Photo by Juni Kriswanto/AFP Photo)

Armed Karo herdsman just back from protecting their cattle herds come down to the river to wash decorative clay markings off their bodies at the end of the day in the Omo Valley, South West Ethiopia. Dus, Omo Valley, Ethiopia, January 2008. (Photo by Brent Stirton/Discovery Communications)

Men stage an attack during a training session for the Olympic Torch Security Team who will be protecting the torch bearers and Olympic flame during the torch relay's progress through the UK, at the Metropolitan Police Training School on March 9, 2012 in London, England. (Photo by Lewis Whyld – WPA Pool /Getty Images)

A patient buried in the hot sand looks out from under a shade that protects his face from the sun in Siwa, Egypt, August 12, 2015. In the searing heat of summer in western Egypt, at the hottest time of the day, sufferers of rheumatism, joint pain, infertility or impotence lie buried neck-deep in the sand of Siwa near Dakrour Mountain. Locals say taking a sand bath is a natural therapy with powers to cure many medical conditions. (Photo by Asmaa Waguih/Reuters)

A soldier helps another with her ear protection at the Terningmoen Camp in Elverum, Norway on March 23, 2017. Soldiers demonstrate their skills and tactics during a contract drill as they train to become part of the world's first all-female special forces unit, the Jegertroppen or “hunter troops”. (Photo by Carolina Reid/NBC News)