If a car explodes, it just leaves behind some radiation for a while. How about if something (car/missile/flamer/plasma) explodes by a building or tree it stays burning for a long while, and enemy can't cross it without being severely damaged (the enemy AI should be smart enough to avoid flame). Maybe the flames can spread and start a bigger fire. Can start forest fires or make city blocks ablaze, depending on the terrain. And I'm not talking flame that goes away after a few seconds, but maybe a more realistic, lengthy time.

And a fire fighter suit (or similar flame suit) exists so you can walk through fire and be immune to flame thrower attacks for a while. And you'll need oxygen tank to get through the smoke. And also use fire extinguishers on flames (have to aim at the base of the flame and sweep sideways or something).

And maybe a "fall to the ground and roll" move to extinguish flames faster if you get ablazed, or look for a water source to jump in.

Sure if implanted right, did you really have to make another topic for this? This belongs in Speculation, Suggestions, and Ideas...

Well thought it can be discussed better in a topic rather than a post.

Suggestion might be asking for more destructible environment, but mainly flame implementation in this topic.

Far Cry 2 did fire very well, bethesda should take some ques from that.