United States Air Force Academy graduates cheer as the United States Air Force Thunderbirds fly over the graduation for the Class of 2021 at Falcon Stadium on May 26, 2021 in Colorado Springs, Colorado. Chairman of the Joint Chiefs of Staff General Mark A. Milley gave the commencement address to the 1,019 graduates from the academy. (Photo by Michael Ciaglo/Getty Images)

A couple pours water on their dogs during a hot day, in Rome, Thursday, August 12, 2021. In Italy, 15 cities received warnings from the health ministry about high temperatures and humidity with peaks predicted for Friday. The cities included Rome, Florence and Palermo, but also Bolzano, which is usually a refreshing hot-weather escape in the Alps. (Photo by Andrew Medichini/AP Photo)

A reconstruction of the first Neanderthal in the Netherlands, nicknamed Krijn, is on display in the National Museum of Antiquities in Leiden, The Netherlands, 06 September 2021. Krijn's face has been worked on for years by the brothers Adrie and Alfons Kennis. (Photo by Bart Maat/EPA/EFE)

A worker piles salvaged e-bikes and scooters on the back of his three wheeler before taking them to be recycled on August 31, 2021 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

A woman in custume attends the 2021 New York Comic Con, at the Jacob Javits Convention Center in Manhattan in New York City, New York, U.S., October 7, 2021. (Photo by Brendan McDermid/Reuters)

A Chinese tourist visits the Mutianyu Great Wall covered in snow on February 23, 2021 in Beijing, China. Affected by the new coronavirus (COVID-19), the number of visitors to Mutianyu Great Wall in 2020 dropped by about 60%. (Photo by Lintao Zhang/Getty Images)

A squatter argues with a police officer during an eviction at a settlement coined the “First of May Refugee Camp”, named for the date people moved on the land designated for a Petrobras refinery, in Itaguai, Rio de Janeiro state, Brazil, Thursday, July 1, 2021, amid the new coronavirus pandemic. (Photo by Silvia Izquierdo/AP Photo)

Aleksandra Miroslaw, of Poland, competes during the speed portion of the women's sport climbing final at the 2020 Summer Olympics, Friday, August 6, 2021, in Tokyo, Japan. (Photo by Tsuyoshi Ueda/Pool Photo via AP Photo)