Costumed revelers pose in front of the Chapell bridge on the opening day of the carnival in Lucerne, Switzerland, 20 February 20​20. The carnival takes place in Lucerne from 20 to 25 February 2020. (Photo by Alexandra Wey/EPA/EFE)

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)

People huddle to get on a bus after the government has eased restrictions on public transport amid concerns over the coronavirus disease (COVID-19) outbreak in Dhaka, Bangladesh, June 4, 2020. (Photo by Mohammad Ponir Hossain/Reuters)

A bull hits a reveller during the first running of the bulls of the San Fermin festival in Pamplona, Spain, July 7, 2018. Each day at 8am hundreds of people race with six bulls, charging along a winding, 848.6-metre (more than half a mile) course through narrow streets to the city's bull ring, where the animals are killed in a bullfight or corrida, during this festival dating back to medieval times and also featuring religious processions, folk dancing, concerts and round-the-clock drinking. (Photo by Vincent West/Reuters)

Communist supporters hold portraits of Soviet leader Josef Stalin as they queue to lay flowers at the grave of Stalin to mark the 139th anniversary of his birth, in Moscow's Red Square, Russia, Friday, December 21, 2018. (Photo by Pavel Golovkin/AP Photo)

Tourists enjoy hot pot and spring at the hotpot shaped spring during winter at a hotel in Hangzhou, east China's Zhejiang Province on December 26, 2018. (Photo by Sipa Asia/Rex Features/Shutterstock)

“Oak Sunrise” by professional photographer Alan Price has won the International Garden Photographer of the Year, “Celebrating Our Oaks” competition, run in partnership with Action Oak. Action Oak is a campaign to protect the UK’s oak trees from threats including pests and diseases. (Photo by Alan Price/IGOTY)

Mud Day Queen Riley Tulgetske, left, embraces Mud Day King Phoenix Crowder during Mud Day at the Nankin Mills Park, Tuesday, July 9, 2019, in Westland, Mich. The annual day is for kids 12 years old and younger. While parents might be welcome, this isn't an event meant for teens or adults. It's all about the kids having some good, unclean fun during their summer break and is sponsored by the Wayne County Parks. (Photo by Carlos Osorio/AP Photo)