A helmet is a form of protective gear worn to protect the head from injuries. More specifically, a helmet aids the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g. UK policeman's helmet) without protective function are sometimes used. The oldest known use of helmets was by Assyrian soldiers in 900 BC, who wore thick leather or bronze helmets to protect the head from blunt object and sword blows and arrow strikes in combat. Soldiers still wear helmets, now often made from lightweight plastic materials.

In civilian life, helmets are used for recreational activities and sports (e.g. jockeys in horse racing, American football, ice hockey, cricket, baseball, camogie, hurling and rock climbing); dangerous work activities (e.g. construction, mining, riot police); and transportation (e.g. motorcycle helmets and bicycle helmets). Since the 1990s, most helmets are made from resin or plastic, which may be reinforced with fibers such as aramids. (source)