A passenger not wearing pants sits in a subway train during the “No Pants Subway Ride” in Prague, Czech Republic, January 10, 2016. The event is an annual flash mob and occurs in different cities around the world in January, according to its organisers. (Photo by David W. Cerny/Reuters)

U.S. singer Katy Perry slips on the icing of a giant cake that she had jumped onto as part of her performance at the MTV Latin America Awards in Guadalajara, in this October 16, 2008 file photo. (Photo by Daniel Aguilar/Reuters)

People in costume take photos during a Halloween event on October 31, 2015 in Lan Kwai Fong, Central District, Hong Kong. Halloween, a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Jerome Favre/Getty Images)

Fisherwomen laying barrels with salt in preparation for herring curing, 1937. (Photo by Topical Press Agency)

This time exposure photo provided by the Santa Barbara County Fire Department shows a series of lightning strikes over Santa Barbara, Calif., seen from Stearns Wharf in the city's harbor, Tuesday evening, March 5, 2019. A storm soaking California on Wednesday could trigger mudslides in wildfire burn areas where thousands of residents are under evacuation orders, authorities warned. (Photo by Mike Eliason/Santa Barbara County Fire Department via AP Photo)

This picture taken on July 9, 2013 shows heavy flood waters sweeping through Beichuan in southwest China´s Sichuan province. Rainstorms sweeping across parts of China have affected millions, causing landslides and disabling transportation in provinces such as Sichuan and Yunnan, state media reported. (Photo by AFP Photo)

A Filipino woman wears a mask to try and protect against the spread of coronavirus in Malate district, Manila City on March 24, 2020. The Philippines has taken drastic measures to combat the spread of Covid-19. The entire country is under strict quarantine and the army is on the streets to monitor compliance. According to official figures, there are 462 positive cases and 33 dead in the Philippines, but it is thought that thousands of cases remain undetected due to lack of resources in a country where millions of people have no access to health care. In the poorest and most crowded areas, it’s almost impossible to adhere to the physical distancing required during quarantine. (Photo by Alejandro Ernesto/The Guardian)

People wearing Christmas hats bath in a pool of watermelon peel during a Christmas service at a hot spring in Luoyang, Henan province, China, December 24, 2016. (Photo by Reuters/Stringer)