Surviving the altitude
Capt. David Cox, 100th Operations Group training assistant chief, flies an aircraft simulator during simulated hypoxia training at Royal Air Force Lakenheath, England, Sept. 17, 2014. Every five years, aircrew are required to undergo hypoxia familiarization training to reintroduce them to signs and symptoms of hypoxia. (U.S. Air Force photo by Airman 1st Class Erin O’Shea/Released)