True story. The closest call I had was several years ago on a fire near Big Sur, in California. I was climbing off the fire after a drop in a Herc (T-130), and passed a Brasillia in United Express colors close enough to see that the left seater was wearing Outdoorsman II sunglasses. We were well inside the TFR.
I don't think the Brasillia crew ever saw us. We were in heavy smoke.
Many times, a TFR doesn't get established until the fire is well established. The problem is for those of us flying initial attack on the fire: well-meaning folks have this innate need to go fly over the fire, putting us all in danger.
I've had brightsparks in 185's try to drop down and fly off my wingtip when I'm doing drops. I've seen lives put in jeopardy and property and homes lost when we had to suspend fire operations until Mr. Hero decided to leave. I've had to escort airplanes out while flying air attack, and then follow up to see that enforcement action was taken for their trouble.
Sometimes a TFR isn't established. It's not uncommon following a fast moving thunderstorm to have a number of smokes reported. We may get launched IA to start dealing with each smoke. While we do try to look out for traffic, we're focused on our mission, which is putting the wet stuff on the red stuff...we don't need folks milling around down there in our way. It's dangerous, in an environment which already ranks as among the most dangerous to be had, period.
Don't rely on the TFR. If you're already in flight when the TFR is issued, you may not know about it. Simply because you haven't received a report of a TFR, don't assume you can go near a fire. One may or may not be in place, but it's best to make a general determination about the fire from a distance, and report it.
Large smokes are seldom in need of reporting. It's the small single tree burns that need to be reported, in order to catch them when they're small. If you are in a position to do so, try to report with either a lat/long, or a radial/distance. Approximating it is okay, because responding ground and air assets will be looking for the smoke too...all you need to do is give general information to get someone headed in the right direction.
When giving a smoke report, try to give the color of the smoke, the size of the fire (remembering that a section, as in section lines, equals a mile, and holds 640 acres...fire size can be deceiving, wind direction, and what the smoke is doing. Is it rising up, laying down, forming a column, puffing, alternating white and black, is it blue, etc. All useful information for determining what to send, and how to deal with the fire. Also include it's proximity to houses or people, a quick note on topography (on the side of a hill, moving upslope with wind, back of a ridge, burning into a rocky outcropping, against a lake, etc). Anything that could be useful.
You can pass it on to ATC or to FSS via flightwatch, and it will get to the right authorities. In this way, you can provide a valueable service, and still steer well clear...its best for everyone, and you're doing the community a big favor.