Staff Sgt. Ricky Valencia, 28th Medical Support Squadron pharmacy technician, combines hydrocortisone and clotrimazole while filling prescriptions at the pharmacy on Ellsworth Air Force Base, S.D., July 23, 2013. Ellsworth pharmacists play a critical role in preventing medication errors, advise physicians on the best medication choices and work directly with patients to ensure they understand how to properly use their medications safely and effectively. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)