I am a photographer for my fire department, as well as assistant to the PIO (FINALLY got a paying job doing this! AWESOME!); and I echo what most here have said - the excitement comes from the people involved in doing the job. A fire without the people is not nearly as dramatic.
When I first started out doing this, the battalion chief (at the time) drilled it into my head - people shots, people shots, people shots. And how right he has been!
If I were to pass on any other advise to aspiring photographers, I'd share these thoughts:
- Keep moving - don't stand in one place.
- Shoot from different angles. My current camera has a flip-out LCD monitor, which I absolutely love; it enables me to shoot higher up or lower to the ground without having to contort myself into all kinds of funky positions.
- Network with people. Get to know your customers (in this case, firefighters). Ask them what they want to see, and if it fits with your vision, then incorporate their feedback into your style of shooting.
- Creativity. Try new stuff.
- Pay it forwards. Pass on what you learn. Knowledge not shared is wasted.