NOUN:
pl. he·roes

1. In mythology and legend, a man, often of divine ancestry, who is endowed with great courage and strength, celebrated for his bold exploits, and favored by the gods.
2. A person noted for feats of courage or nobility of purpose, especially one who has risked or sacrificed his or her life.

The example you gave is only one form of hero. Your instance is one where heroes save lives at the possible sacrifice of their own and it is immediately known if they are successful or not. A person doesn't need to be in immediate danger to require saving and sometimes you won't even realize you were saving a life until many years later.

Please look again at the second definition of hero up there.

Now, I've heard you talk about your class and it definitely takes courage to walk in that door day after day. Then there's the sacrifice aspect. Without a doubt you have given up your life for the benefit of these kids, even if it's not in the physical sense.

Don't you ever, not for one second, believe you are anything but a hero in the truest sense of the word.

__________________
Put me on wheels and I'll turn tricks.

Clever? Nah, I ran out of that years ago. But if you find this, let me know, k?
"The road goes ever on..." ~ Tolkien

In memory of my friend skip...
Go then, there are other worlds than these