I haven't played the fire fighter career for a while, so I'm not sure when the problem started. Suddenly my firefighter Sim won't interact with fires. He responds to the emergency, but when he gets there he just stands and does nothing. I cannot click on the fire at all. Everything else about the career seems to be working, except that I don't receive a notification about the carpool, although it does turn up. Not sure if that is relevant or not.

on which patch level are you? some career related bugs were adressed in patches. but there still seem to be bugs within most Ambitions Careers! (and other EP related Carerrs in general). see if patching to the current 1.67 version helps first.Game Help:TS3 Patching:Patch Download

also from EA Help a suggestion to check if the outfit is a problem? sounds weird but i dont want to hold it back so here ya go

also there are a lot of matches when searching for sims 3 firefighter career bug - i cant check them all but maybe you want to take a look at it

I'm stupid! There was a mod directly related to fires: Friendly fiers (sic) by Jadaytime, Its to stop Sims panicking every there's a fire. That seems to have been to culprit. The problem seems to be solved, although I'm still having to manually tell my sim to go to his carpool.

out of curiosity concerning "friendly fires"
the culprit cause its conflicting generally or cause it was outdated?

I installed this mod before I got patched to 1.67. It didn't cause any problems before that, so I should say its outdated. Serves me right for putting things into separate folders, I just forgot it was there. Thanks for your interest.