In this January 3, 2018 photo several female Gelada baboons, also known as bleeding-heart baboons, cuddle with their youngs in order to keep warm at the Wilhelma zoo in Stuttgart, Germany. (Photo by Sebastian Gollnow/DPA via AP Photo)

This photo taken on December 2, 2015 shows a lenticular cloud forming as white streaks from airplanes mark the blue sky, in a rare atmospheric phenomena above the town of Gevgelija on December 2, 2015. Lenticular clouds have been regularly confused for UFOs throughout history due to the their smooth, round or oval lens-shaped structure. (Photo by Armend Nimani/AFP Photo)

Pigeons cool down at a public fountain on a hot summer day at University Plaza in downtown Bucharest, Romania, 10 June 2020. Temperatures in Bucharest reached 30 degrees Celsius. (Photo by Robert Ghement/EPA/EFE)

An Indian worker crosses a street holding a shovel during monsoon rains in Prayagraj, in the northern Indian state of Uttar Pradesh, Wednesday, July 29, 2020. (Photo by Rajesh Kumar Singh/AP Photo)

A person wearing a face mask is reflected in an art work entitled “A=V” by Ben Cullen Williams, amid the coronavirus disease (COVID-19) outbreak, in Covent Garden, London, Britain on October 16, 2020. (Photo by John Sibley/Reuters)

Local residents crowd a swimming pool during a hot weather in Suining, Sichuan province, 27 July 2008. (Photo by Reuters/Stringer)

A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

New Year's Eve revellers from Asia with Australian flags and balloons in the shape of the new year 2020 in Sydney, Australia on December 31, 2019. (Photo by Richard Milnes/Rex Features/Shutterstock)