Scarlett Zelaya, 10, of Woodbridge, VA cools off under a water mister while visiting the Smithsonian National Zoological Park on Wednesday July 21, 2021 in Washington, DC. (Photo by Matt McClain/The Washington Post)

A farmer waits for customers at a wholesale vegetable market in Prayagraj, Uttar Pradesh state, India, Sunday, July 25, 2021. (Photo by Rajesh Kumar Singh/AP Photo)

Gina Di Meo, journalist from ANSA sits during a media preview of Summit at One Vanderbilt in New York, October 1, 2021. The Summit viewing deck is spread across the top four floors on One Vanderbilt in Manhattan, the fourth tallest building in the city. (Photo by Timothy A. Clary/AFP Photo)

People take photos during the Loy Krathong festival which is held as a symbolic apology to the goddess of the river in Chiang Mai, Thailand, November 19, 2021. (Photo by Soe Zeya Tun/Reuters)

A pedestrian wearing a face mask to protect against coronavirus, walks in front of a mural, at a metro station in Athens, Greece, Monday, November 15, 2021. Authorities say the rate of death related to COVID-19 in Greece has reached its highest level in six months as roughly one-third of the country's population remains unvaccinated. (Photo by Thanassis Stavrakis/AP Photo)

An Afghan hawker selling balloons walks along a path in a ground in Chaman-e-Hozori area in Kabul on December 10, 2021. (Photo by Ahmad Sahel Arman/AFP Photo)

A Chinese tourist uses the scarf of a friend as she is helped while she and others struggle to climb in the wind on an icy section of the Great Wall at Badaling, on a cold day after a snowfall on November 30, 2019 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

A man wearing a face mask walks his dog as he pulls a trolley after shopping in Beijing on February 13, 2020. The number of deaths and new cases from China's COVID-19 coronavirus outbreak spiked dramatically on February 13 after authorities changed the way they count infections in a move that will likely fuel speculation that the severity of the outbreak has been under-reported. (Photo by AFP Photo/China Stringer Network)