I live a street over from two large hospitals (and a nursing college). When I was in hospital after Danny was born, I spent my time watching the helicopters land at Children's hospital next door. Not the sort of thing I wanted to see, but nonetheless, the stream was near constant. Nebraska is a largely rural state, and in an emergency, being taken to hospital by ambulance isn't always possible. Eight years later, I'd forgotten all of that until we moved here, and noticed the steady helicopter traffic.
In our previous home, we heard helicopters all day and night from the National Guard base nearby. Sometimes, they'd fly pretty low over the house in the wee hours, but eventually I learned to tune it out. The helicopters we hear now are smaller, they sound different, and come with the knowledge that they are carrying critically ill people to the city for treatment. It does give me pause, much like an ambulance wailing down the street-I find myself (not always silently) wishing them well.
On the positive side, we live in a neighbourhood full of medical types (an a nursing student next door) so if I fall over in the street, the odds are in my favour that someone will administer CPR. Maybe. At least I won't need a helicopter ride across the street.