Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)

Hindu devotees play with coloured powders during Holi celebrations at the Bankey Bihari Temple on March 21, 2011 in Vrindavan, India. Holi, the spring festival of colours, is celebrated by Hindus around the world in an explosion of colour to mark the end of the winter. (Photo by Majid Saeedi/Getty Images)

A body surfer rides a high wave at the Wedge on September 1, 2011 in Newport Beach, California. Waves measuring up to 20 feet pounded the beach. A winter storm off the coast of Australia and New Zealand brought unusally hgh serve to the Southern California beaches. (Photo by Kevork Djansezian/Getty Images)

Migrating starlings fly in formation near the southern Israeli town of Rahat February 2, 2015. The phenomenon, known as murmuration, is most common during the winter months. (Photo by Nir Elias/Reuters)

Bavarian farmers load their cows on a boat before they drive over the picturesque Lake Koenigssee, Germany, October 3, 2015. Before the winter season approaches the farmers have to drive their cattle down from their Alpine meadows to a narrow valley that can only be reached by boat. (Photo by Michael Dalder/Reuters)

Two women jump into a frozen pond as they compete in the Polar Plunge at Frozen Dead Guy Days in Nederland, Colorado March 14, 2015. The winter festival in the small mountain town commemorates the 1994 discovery of the corpse of Bredo Morstol, which is now housed in a shed on dry ice above the town. (Photo by Rick Wilking/Reuters)

A girl rides on a train as she takes part in the first edition of the No Pants Subway Ride in Bucharest, Romania, Sunday, January 11, 2015. The No Pants Subway Ride is an annual which was started in 2002 by Improv Everywhere in New York, the goal is for riders to get on the subway train dressed in normal winter clothes without pants and keep a straight face. (Photo by Vadim Ghirda/AP Photo)

A man wearing a native costume named “Woman Carrying Husband” poses ahead of the Carnival in Sostanj January 15, 2015. Slovenians and members of various ethnological groups celebrate the annual carnival, also known locally as Pust, by wearing traditional masks and costumes to symbolically “chase away” the winter. Prust runs from February 7 to 17 this year. (Photo by Srdjan Zivulovic/Reuters)