An air ambulance is a specially outfitted aircraft that transports injured or sick people in an medical emergency or over distances or terrain impractical for a conventional ground ambulance. These and related operations are called aeromedical. In some circumstances, the same aircraft may be used to search for missing or wanted people. Like ground ambulances, air ambulances are equipped with medical equipment vital to monitoring and treating injured or ill patients. Common equipment for air ambulances includes medications, ventilators, ECGs and monitoring units, CPR equipment, and stretchers. A medically staffed and equipped air ambulance provides medical care in flight—while a non-medically equipped and staffed aircraft simply transports patients without care in flight. Military organizations and NATO refer to the former as Medical Evacuation (MEDEVAC) and to the latter as Casualty Evacuation (CASEVAC).