The carriage  of invalid passengers by air.
D000337:Aerospace Medicine; D000531:Altitude; D001274:Atmospheric Pressure; D002318:Cardiovascular Diseases; D003141:Communicable Diseases; D003920:Diabetes Mellitus; D004432:Ear, Middle / Q000601:surgery; D005221:Fatigue / Q000209:etiology; D005767:Gastrointestinal Diseases; D006402:Hematologic Diseases; D006801:Humans; D000860:Hypoxia / Q000209:etiology; D001523:Mental Disorders; D009422:Nervous System Diseases; D012140:Respiratory Tract Diseases; D013515:Surgery, Oral; D014187:Transportation of Patients