A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

Mexico City resident Romina Montoya takes a playful selfie wearing a protective face mask over her eyes and nose, in Playa del Carmen, Quintana Roo state, Mexico, Wednesday, January 6, 2021. Concern is spreading that the critical winter holiday tourism success could be fleeting because it came as COVID-19 infections in both Mexico and the United States were reaching new heights. (Photo by Emilio Espejel/AP Photo)

A face mask discarded in a forest in the Taunus region near Frankfurt, Germany, Sunday, October 18, 2020. (Photo by Michael Probst/AP Photo)

Teenage girls are all steamed up these days about straight hair. The steam iron is replacing the huge rollers on which countless teens slept every night to achieve the height and curls fashionable until. The same girls endure having their hair stretched to absolute straightness on the ironing board, and then ironed to keep it that way. Unlike the roller setting, this takes teamwork. Gay Stilley, 14, goes through an ironing session with a couple of her friends at the Stilley Home in Glen Oaks, Queens, New York City on December 23, 1964. With a wary eye, Gay tries to watch the straightening process as one friend stretches her hair with a comb and another does the ironing, in the Stilley kitchen. (Photo by Marty Zimmerman/AP Photo)

A Palestinian man waves from his home as a clown and a man in a costume perform to entertain people amid concerns about the spread of the coronavirus disease (COVID-19), in Khan Younis in the southern Gaza Strip on April 19, 2020. (Photo by Ibraheem Abu Mustafa/Reuters)

A baby Chimpanzee plays in its enclosure at Taronga Zoo July 14, 2006 in Sydney, Australia. (Photo by Ian Waldie/Getty Images)

Kirby Chambliss of the United States flies in formation with Matt Hall of Australia, Yoshihide Muroya of Japan and Nigel Lamb of Britain prior to the third stage of the Red Bull Air Race World Championship in front of the Petronas Towers in Kuala Lumpur, Malaysia, on May 15, 2014. (Photo by Joerg Mitter/Red Bull via Reuters)

Tatyana Abramova, 33, plays with her home fox Plombir at her countryside house outside Siberian city of Novosibirsk on September 12, 2020. The official start of the Soviet experiment to better understand the domestication of animals by humans began in 1959, and was initiated by geneticists Dmitri Beliaiev and Lioudmila Trout on a farm in Akademgorodok, the scientific center of excellence in Siberia. Their primary objective was to domesticate foxes, to understand how the ancestor of wolves, another canine, evolved into a loyal and loving dog. And understand what this domestication tells us about the genetic evolution of species. (Photo by Alexander Nemenov/AFP Photo)