U.S. Air Force Tech. Sgt. Desiree Beltran and Senior Airman Mason Wyman, both 633rd Aerospace Medical Squadron altitude chamber personnel, set up the altitude chamber for a training session at Langley Air Force Base, Va., June 25, 2014. Altitude chamber personnel ensure the chamber participants remain safe as they undergo the effects of hypoxia for training purposes. (U.S. Air Force photo by Senior Airman Austin Harvill/Released)