U.S. Air Force Airman 1st Class Chelsea Ellman, left, 633rd Medical Operations Squadron medical technician, and Courtney Winter, right, 633rd MDOS license practical nurse, donate blood during the Armed Services Blood Program Blood Drive at Langley Air Force Base, Va., May 28, 2014. Donations from the blood drive are used to support military hospitals and Service members downrange. (U.S. Air Force photo by Senior Airman Connor Estes/Released) (photo cropped and sharpened for effect)

U.S. Navy Hospital Corpsman 3rd Class Arwin Mejia, Naval Medical Center Portsmouth laboratory technician, draws blood from U.S. Air Force 1st Lt. Jewelyn Delacruz, 633rd Medical Operations Squadron clinical nurse, during the Armed Services Blood Program Blood Drive at Langley Air Force Base, Va., May 28, 2014. The Armed Service Blood Program is responsible for all active duty personnel worldwide, family members and dependents in military medical facilities. They also send blood donations downrange to Service members every week. (U.S. Air Force photo by Senior Airman Connor Estes/Released) (photo cropped and sharpened for effect)