Ambulance
Air ambulances became more common in the late 20th century.  They are helicopters that carry much of the same equipment as a normal ambulance.  In the United States, the Coast Guard runs a public air ambulance service using helicopters. These are often needed when emergencies happen at sea. There are also privately owned air ambulance services that provide for a wider range of needs, including international transport. Air ambulances are very useful when an emergency happens in a place that is hard to get to quickly by ground travel.