A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Festival goers dance during Glastonbury Festival at Worthy Farm, near Pilton, Somerset, Britain, 23 June 2017. The outdoor festival runs from 21 to 25 June. (Photo by Nigel Roddis/EPA)

Visitors hold ice blocks to cool themselves in hot weather at a water park on June 23, 2016 in Chongqing, China. Citizens and visitors escaped high temperature at a water park in Yangren Jie (also known as Foreigner Street), Nan'an District of south China's Chongqing. (Photo by VCG/VCG via Getty Images)

A woman wearing a wedding dress takes part in the so-called “brides' match” at the FIFA Fan Fest in Kazan, a host city for the 2018 FIFA World Cup, Russia June 30, 2018. (Photo by Alexey Nasyrov/Reuters)

A worker fills a public bus with diesel as the bus driver and passengers look on, at a fuel station in Kolkata, India, February 1, 2017. (Photo by Rupak De Chowdhuri/Reuters)

“There are over 680 documented species of the sac fungus genus Ophiocordyceps, and one of the best known of these is Ophiocordyceps sinensis, colloquially known as caterpillar fungus. The fungus is known in Tibetan as yartsa gunbu or yatsa gunbu. O. sinensis is known in the West as a medicinal mushroom and its use has a long history in Traditional Chinese medicine as well as Traditional Tibetan medicine. The highly valuable fungus-caterpillar combination is hand-collected and is used as an aphrodisiac and as a treatment for a variety of ailments from fatigue to cancer”. – Wikipedia

Photo: Nomads dig for Chinese caterpillar fungus from a mountain May 25, 2007 in Guide County, Hainan Prefecture, Qinghai Province, China. Nomads can earn about 2,000 yuan to 5,000 yuan (about U.S. $260 to $653 ) through their work during the fifty-day Chinese caterpillar fungus gathering season. (Photo by China Photos/Getty Images)

Shoppers wrestle over a television as they compete to purchase retail items on “Black Friday” at an Asda superstore in Wembley, north London November 28, 2014. Britain's high streets, malls and online sites were awash with discounts on Friday as more retailers than ever embraced U.S.-style “Black Friday” promotions, seeking to kickstart trading in the key Christmas period. In the United States the Friday following the Thanksgiving Day holiday is called Black Friday because spending usually surges and indicates the point at which American retailers begin to turn a profit for the year, or go “into the black”. (Photo by Luke MacGregor/Reuters)

Nine year old girl Barsati reacts while walking on a tightrope in Mumbai on February 11, 2014. Barsati, and her younger brother Rajababu, (4) earn an average of around 2000 rupees (32 dollars) per day from pedestrians and tourists performing various acts on the tightrope near the city's iconic landmark Gateway of India. (Photo by Indranil Mukherjee/AFP Photo)