U.S. Staff Sgt. Aaron Kostiuk, 435th Security Forces Squadron ground combat readiness training center instructor, stands up after applying a tourniquet to himself during exercise Frozen Defender in Grostenquin, France, Jan. 14, 2020. Frozen Defender tests the squadron’s capabilities in a contested environment under harsh conditions. The use of self-aid and buddy care allowed the Defenders to continue the mission and thwart any hostile forces from taking control of the airfield. (U.S. Air Force photo by Staff Sgt. Devin Boyer)