Probably the dumbest addon you'll ever want. Turn your helm on and off when in combat or resting... Or just toggle on and off with a simple chat command
/ch on - Helm visible
/ch off - Helm hidden
/ch combat - Helm visible in combat, hidden when not in combat
/ch rest - Helm hidden when in a city or inn, visible when out in the world
/ch status - find out what your current mode is.