You really have to appreciate that firefighters enter life-threatening situations, and are exposed to hazardous conditions over long periods of time. After something like 20 years of service, this former colleague became eligible for some kind of district-funded health benefits to cover the cost of treatment of lung cancer... why? you may ask.
Because after 20 years of firefighting service your likelihood of lung cancer is increased in a statistically significant way.
Public service is an excellent calling and I absolutely encourage you to pursue it - I think trade schools offer programs to help you with this career? There's likely several other paths I don't know about.
Just be sure that you recognize early on that the job is dangerous and physically demanding in a number of ways.