U.S. Air Force Staff. Sgt. Trent Carter, Detachment 1, 66th Training Squadron survival evasion resistance and escape specialist, demonstrates the construction of a thermalized A-frame shelter Feb. 6, 2014, Eielson Air Force Base, Alaska. Carter helps provide arctic survival training to U.S. military and allies. (U.S. Air Force photo by Senior Airman Joshua Turner/Released)