A man pours wine into the hands of a women as they sit in a hot bath with coloured water representing wine at the Hakone Kowaki-en Yunessun spa resort during an event marking Beaujolais Nouveau Day in Hakone west of Tokyo, November 19, 2015. (Photo by Thomas Peter/Reuters)

Young people fight for fun with their pillows, during the International Pillow Fight Day at the Place des Grottes, in Geneva, Switzerland, Saturday, April 4, 2015. The annual International Pillow Fight Day takes place in hundreds of cities around the world. (Photo by Salvatore Di Nolfi/AP Photo/Keystone)

A patient buried in the hot sand looks out from under a shade that protects his face from the sun in Siwa, Egypt, August 12, 2015. In the searing heat of summer in western Egypt, at the hottest time of the day, sufferers of rheumatism, joint pain, infertility or impotence lie buried neck-deep in the sand of Siwa near Dakrour Mountain. Locals say taking a sand bath is a natural therapy with powers to cure many medical conditions. (Photo by Asmaa Waguih/Reuters)

Developer of “Hizamakura”, or lap pillow, Makoto Igarashi, introduces the product at Trane Co., Ltd.'s HQ on December 14, 2004 in Tokyo, Japan. (Photo by Koichi Kamoshida/Getty Images)

A woman takes part in a four-minute flash mob pillow fight at the Old Town Square in Prague, Czech Republic, December 22, 2016. (Photo by David W. Cerny/Reuters)

A woman jumps into water from the roof of Murru prison, an abandoned Soviet prison, in Rummu quarry, Estonia, during hot weather July 4, 2015. During the Soviet time, Rummu quarry was used as a mining site for Vasalemma marble and most of the workforce came from among the detainees of Murru prison. When the prison closed after 1991, pumps that once kept the quarry and the prison dry were shut down, causing water to fill the quarry. It has become an unofficial and unguarded swimming and diving spot, attracting locals and tourists. (Photo by Ints Kalnins/Reuters)

Ukrainian teenagers hit each other with pillows during a large pillow fight in downtown Kiev, Ukraine, 24 April 2016. About hundred people took part in the event “Pillow battle 2016” in Kiev. (Photo by Roman Pilipey/EPA)

A family of children share a bath in Japan, circa 1965. (Photo by Three Lions/Hulton Archive/Getty Images)