Who is a first responder? Anyone who is at the scene first, usually us!
That would be, say, someone being robbed, burgled, raped or at the scene of a fire or earthquake or any number of other events including health issues.
It is simply the person or persons who respond/s first.
Simple and not.
I'm not putting down emergency crews. I've seen and known many who serve honorably, even to 'the last measure'.
I'm just saying those to whom emergencies happen can sometimes know and do better first off.
It's part of helping oneself. Such as self defense.
We can't wait to be rescued. We must take the initiative ourselves.
Developing the ability to at least take initial action is endemic to survival of each of us and for the Republic.
Waiting is more than wasteful.
Wait for help in picking up the pieces -s-.