If every soldier, firefighter, ambo, is a hero what do you call a soldier who gets the US Medal of Honor?
What do you call a fireman who gets the Public Safety Officer Medal of Valor?
Or someone who gets the Presidential Medal of Freedom?
If every one in uniform is a hero then describe this person: Fallen Sergeant Robert Wilson III (Philadelphia Police Department, PA) for giving his life to protect innocent civilians. Sergeant Wilson put himself in harm’s way during an armed robbery, drawing fire from the assailants and suffering a mortal wound as he kept store employees and customers safe.
A hero is not a normal person doing their duty. A hero is a person who does a selfless act of courage far above and beyond their duty.
I do think that we have experienced a LOT of "grade inflation" when it comes to terms like hero, and though I assume most of it is well meaning, it unintentionally does a disservice to REAL heroes who have voluntarily put their own welfare or even their own life, at great risk to benefit others. It's gotten so that the word hero is often used just to make someone feel good for doing just what is expected of them even when they were in no real danger, and it's especially overused in professional sports where the supposed "hero" is paid more in a week than most of us will see in a lifetime, and the biggest risk he encountered was a sprained ankle (fully insured, of course).
But to me, rather than a title, the term "first responder" is a descriptive one that applies to all those who arrive at emergency situations and attempt to help those in need , often in disregard to the possibility that the dangerous situation is not yet fully neutralized. Usually, but not always, first responders are there in some official capacity such as fireman, ambulance crew, police officer, marine patrol, Coast Guard, etc. but not all firemen or police are first responders. Only very occasionally a first responder will do something that I would actually call heroic, but I consider all of those whose job description or own personal code requires them to rush in to help out when others are rushing to get away from the danger or unpleasantness that exists to be people worthy of more admiration and respect than most are.
You're right that the definition of many terms such as these vary as you travel and cross physical or ethnic borders or are translated into another language, but I think we all know a heroic action when we see one, and when something bad happens, we can see who the first responders are, and aren't, no matter what uniform they have on.