Adding to the stop, drop, and roll idea, I think a certain button combo should activate an animation that removes the burn upon activation, but leaves you vulnerable for a couple seconds. Maybe if you sprint slide while burning, you recieve a prompt to hold (your reload button here) in order to start the animation. The burn would still promote a disengage from combat (DoT would still be viable), and you wouldn't be powerless to live even if (and especially) you had defeated the one who burned you.