Washington Caution: Hard Hat Area is a warning sign that signals danger in a construction or industrial site. It is designed to alert people of the potential for hazards in the area and to remind them to wear protective headgear. The sign is typically yellow with black lettering, and often includes other graphical elements such as a hard hat icon. There are several types of Washington Caution: Hard Hat Area signs, including those that are printed on durable aluminum, plastic, or paper material; signs that are printed on rigid or flexible reflective sheeting; and signs that are printed on self-adhesive vinyl. Each of these signs is designed to help ensure that workers, visitors, and passersby are aware of the potential danger in the area, which can help to reduce the risk of injury or death in the workplace.