Bulgarian Col. Lyubomir Alexiev, Military Medical Academy doctor, uses the hypoxya familiarization trainer during a visit to Ramstein Air Base, Germany, on Dec. 14, 2011. Bulgarian military medical members came to Ramstein to learn how the Contingency Aeromedical Staging Facility personnel move wounded warriors out of the battlefield. (U.S. Air Force photo/Senior Airman Aaron-Forrest Wainwright)