Assuming you are refering to Most Wanted.
It tells the level of "heat" your cars have. That is, the level of
interest from cops. The more heat, the more aggressive (and
faster/harder to immobilize cars) the cops will be. Goes from 1 up to 5
as the game progresses (and more in special circumstances late in the game).
Post by Biasiutti RiccardoHi,
what is the flame indicator in the garage ?