Your brown fat remains; it doesn’t “burn off” and if anything, using the Cool Fat Burner will increase your BAT stores.
BAT burns your white fat, the fat on your stomach, hips, and so on. If anything, as you get slimmer, exercise, and continue to use the Cool Fat Burner, you may actually gain more brown fat.
Remember, brown fat is embryologically related to muscle tissue; it’s closer to muscle than fat. You don’t burn it off, like regular white fat.