This picture taken on January 25, 2015 shows a participant taking part in an ice water challenge in Zhangjiajie, central China's Hunan province. Participants were required to stay in an ice pond, holding an ice block while eating ice-cream with an electric fan blowing at them. (Photo by AFP Photo/Stringer)

Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

Udomsak Ratanotayo, left, and Suttinan Boonsomkiat wear storm trooper costumes while donating blood at the Thai Red Cross in Bangkok, Thailand on Monday, April 28, 2014. Thai Star Wars fans will donate blood and give toys at an orphanage as part of a promotional campaign. (Photo by Sakchai Lalit/AP Photo)

Uniformed participant dance during a mass rally and parade in the capital's main ceremonial square, a day after the ruling party wrapped up its first congress in 36 years by elevating him to party chairman, in Pyongyang, North Korea, May 10, 2016. (Photo by Damir Sagolj/Reuters)

Artist Joe Hill poses on his 3D artwork, from the “Joe and Max” project as part of an advertising campaign, during its presentation at a park in Moscow, Russia, July 4, 2015. (Photo by Sergei Karpukhin/Reuters)

A beluga whale sprays water towards visitors during a summer attraction at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on July 20, 2015. Tokyo's temperature climbed over 34 degree Celsius on July 20, one day after the end of the rainy season. (Photo by Toshifumi Kitamura/AFP Photo)

A man looks on from the sea as Italian model and actress Elisa Sednaoui poses for photographers a day before the 72nd Venice Film Festival in Venice, Italy, September 1, 2015. Sednaoui will be hosting the opening and closing ceremonies of the film festival. (Photo by Stefano Rellandini/Reuters)

A Lebanese man carries an injured woman away from the site of a car bomb explosion in a Shiite area and stronghold of the Lebanese militant group Hezbollah at the southern suburb of Beirut, Thursday January 2, 2014. A large explosion has rocked a stronghold of the Shiite Hezbollah group in the southern suburbs of the Lebanese capital. (Photo by Hussein Malla/AP Photo)