U.S. Air Force Lt Col Samuel Mcintyre, NATO Allied Command Transformation deputy chief of staff military assistant, pilots a flight simulator while taking hypoxia training at 1st Operations Group aerospace and operational physiology, Joint Base Langley-Eustis, Va., Dec. 5, 2017. Some symptoms of hypoxia may include tingling in extremities, affected vision, nausea, light headedness, euphoria and/or belligerency. (U.S. Air Force photo by Airman 1st Class Tristan Biese)