A barrel shroud is a covering attached to the barrel of a firearm that partially or completely encircles the barrel, which prevents operators from injuring themselves on a hot barrel. Slides, extensions of the stock that do not fully encircle the barrel, and the receiver (or frame) of a firearm itself are generally not described as barrel shrouds, though they in fact do act as such. Barrel shrouds are commonly featured on air-cooled machine guns, where sustained rapid or automatic fire leave the barrel extremely hot and dangerous to the operator. However, shrouds can also be utilized on semi-automatic firearms, as even a small number of shots can heat up a barrel enough to injure an operator in certain circumstances.
Barrel shrouds are also used on pump-action shotguns. The military trench shotgun features a ventilated metal handguard with a bayonet attachment lug. Ventilated handguards or heat shields (usually without bayonet lugs) are also used on police riot shotguns and shotguns marketed for civilian self-defense. The heat shield also serves as an attachment base for accessories such as sights or sling swivels.