Helmet including vent and actuator assembly for moving vent shutter and methods of using same

The invention is directed to protective helmets having vents with a manually operable vent shutter and methods of using same. In one embodiment, a helmet includes an outer shell, an upper liner, a lower liner, and a vent shutter positioned within a space defined by the upper and lower liners. The helmet includes at least one vent formed through the outer shell, upper liner, and lower liner. The helmet further includes an actuator assembly operable to move the vent shutter to open and close the at least one vent. The actuator assembly includes an engagement member, such as a gear. The engagement member engages the vent shutter and effects movement of the vent shutter when rotated relative to the vent shutter about the rotation axis. In another embodiment, the upper liner may be omitted and the vent shutter may be disposed between the interior of the outer shell and the lower liner.