However, it does wear out for many. Burnout can also happen with time. There are many articles on burnout. It is important to share your concerns with your EMS supervisors - if you have a call that is bothering you.
Stopping at incidents when off duty should be personally decided - if you can be prepared/scene safety/and have the time for the full duration of the call. There are of course many other conditions/concerns. Note: If your vehicle is advertised with lightbars and other insignias - you may have a predeciding factor. After about my first five years of EMS Lic plates, etc - I decided not to "advertise". However, if there was an appearance of life threatening situation with no EMS units on the scene of an incident, I would always choose it as an obligation morally to stop and assist.