Abstract: A head protection system includes an open-ended tubular cap band of flexible material for partially encircling the head of a wearer generally at the level of the wearer's forehead. A belt member is slidably received through the tubular cap band and adjusts to accommodate the size of the head of the wearer. A crown member of a partial hemispherical shape has an equator region attached to the tubular cap band. In one embodiment, the opposed ends of the belt member include mutually engageable closure devices for joinder to accommodate the wearer's head. In another instance, the belt member is continuous and composed of flexibly expansible material. In still another instance, an elongated air bladder of resilient rubber-like material is received through the cap band with an air pump connected to the interior of the air bladder to selectively fill the air bladder with air.