Staff Sgt. Shea Townsend, 39th Comptroller Squadron cashier, dons a gas mask during a base wide exercise April 29, 2015, at Incirlik Air Base, Turkey. As part of the exercise, Airmen from across Incirlik gathered to participate in chemical, biological, radiological and nuclear warfare refresher training. (U.S. Air Force photo by Senior Airman Krystal Ardrey/Released)