Ice swimmer Klaudia prepares to swim in a filled up water kettle in an ice cave inside the Nature Ice Palace, with a hight of 3,250 meters (10,663 feet) above sea level, at Hintertux Glacier near Hintertux, some 480 kilometers (298 miles) western of Vienna, Austria, 28 July 2018. (Photo by Christian Bruna/EPA/EFE)