A half-naked participant wears a gas mask as he takes part in the second “Guangzhu (naked) Run” on a winter morning at the Olympic Forest Park in Beijing, on February 24, 2013. About 100 people joined this event, which required them to run wearing only their underwear for 3.5 km (2.2 miles), as a way to promote environmentally-friendly lifestyles. (Photo by Reuters/China Daily via The Atlantic)
