U.S. Air Force Senior Airman Robert Hart, 633rd Medical Operations Squadron cardiopulmonary laboratory technician, intubates a medical mannequin to simulate opening an airway at Langley Air Force Base, Va., Aug. 6, 2014. Intubation is the placement of a tube into the trachea of those who are unconscious or unable to maintain the airway. (U.S. Air Force photo by Senior Airman Connor Estes/Released)