Medical emergencies.
D000401:Aircraft; D000552:Ambulances; D004632:Emergency Medical Services / Q000266:history / Q000458:organization & administration*; D004634:Emergency Medical Technicians / Q000193:education; D004635:Emergency Medicine / Q000193:education; D004636:Emergency Service, Hospital / Q000458:organization & administration; D005060:Europe; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049690:History, Ancient; D049691:History, Medieval; D014481:United States; D014857:Warfare