Young demonstrators (many shirtless) shout and cheer as they overturn a truck trailer in the Reflecting Pool on the Mall facing the Washington Monument during the “Honor America Day Smoke-In” thrown by marijuana activists to protest the official “Honor America Day” ceremonies being held at the Lincoln Memorial, Washington, DC, July 4, 1970. (Photo by David Fenton/Getty Images)

A showgirl in a face mask stands by the door at the reopening of Bally's Las Vegas hotel and casino, Thursday, July 23, 2020, in Las Vegas. The casino reopened for the first time since March following a closure to prevent the spread of the coronavirus. (Photo by John Locher/AP Photo)

Commuters wearing face masks jostle for a ride on a bus discarding social distancing guidelines in Kolkata, India, Tuesday, July 21, 2020. With a surge in coronavirus cases in the past few weeks, state governments in India have been ordering focused lockdowns in high-risk areas to slow down the spread of infections. (Photo by Bikas Das/AP Photo)

A couple wears face masks as they share a moment during sunset on January 31, 2020 in Hong Kong, China. With over 9800 confirmed cases of Novel coronavirus (2019-nCoV) around the world, the virus has so far claimed over 200 lives. (Photo by Anthony Kwan/Getty Images)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

A protester pours Coca-Cola on the face of a comrade to diminish the effects of tear gas during a crackdown by security forces on a demonstration against the military coup in Yangon's Thaketa township on March 19, 2021. (Photo by AFP Photo/Stringer)

It doesn’t make for the most flattering photoshoot, but there is a reason these zebras at Lewa wildlife conservancy in Kenya in the second decade of August 2025 are stood head to tail: they use their tails to swat flies from each others’ faces. (Photo by Andrew Campbell/Solent News & Photo Agency)

“Theyyam”. Preparation for the Theyyam performance in the surroundings of Kasaragod city. Theyyam is a popular ritual dance form of North Kerala, particularly in Kannur and Kasargod districts. The Theyyam represents a mythological, divine or heroic character. Make up of Theyyams is done by specialist. There are different types of face painting for which primarily and secondary colours are used. Therefore it is essential that the makeup man should have perfect knowledge of primary and secondary colour combinations. Sometimes, it takes several hours to paint each face. Photo location: Kasaragod, India. (Photo and caption by Rafal Ziejewski/National Geographic Photo Contest)