| A helmet is a form of protective | | | | War I as late as 1915, when they were |
| clothing worn on the head and usually | | | | replaced by the new French Adrian |
| made of metal or other hard substance, | | | | helmet. It was soon followed by the |
| such as Kevlar, resin fiber, or plastic | | | | adoption of similar steel helmets by the |
| typically for protection of the head in | | | | other warring nations. |
| combat, or in civilian life, from sports | | | | World War I and its increased use of |
| injuries, falling objects or high-speed | | | | heavy artillery had renewed the need for |
| collisions. | | | | steel helmets, which were quickly |
| Helmets are common in the military, | | | | introduced by all the combatant nations |
| construction, mining, and some sports, | | | | for their foot soldiers. In the 20th |
| including american football, baseball, | | | | century, such helmets offered protection |
| ice hockey, equestrian sports, | | | | for the head from shrapnel and spent, or |
| motorsports, and rock climbing. | | | | glancing bullets. |
| Motorcycle helmets and bicycle helmets | | | | The use of protective helmets by |
| are compulsory headgear in some | | | | millions of fighting men in the two |
| jurisdictions; in the United Kingdom | | | | world wars increased awareness of "hard |
| only Sikhs are allowed to ride | | | | hat" protection. By the 1950s, hundreds |
| motorcycles without wearing motorcycle | | | | of new applications for helmets were |
| helmets. Bicycle helmet compulsion and | | | | found. The helmet offered an unexpected |
| even strong promotion has been a heated | | | | advantage: Symbolism. It can signify |
| subject of debate amongst cyclists and | | | | that, like a soldier, the wearer is |
| scientists since at least the 1990's, | | | | someone qualified for or capable of a |
| lately focusing on alleged net | | | | certain task or activity, such as |
| protective effect at the population | | | | construction, operation of heavy |
| level. | | | | machinery, or participation in certain |
| Helmets were among the oldest forms of | | | | sports. |
| combat protection, and are known to have | | | | Today's militaries often use |
| been worn by ancient Greeks, Romans, | | | | high-quality helmets made of ballistic |
| throughout the Middle Ages, and up to | | | | materials such as Kevlar, which have |
| the end of the 1600s by many combatants. | | | | excellent bullet and fragmentation |
| At that time, they were purely military | | | | stopping power. Some helmets also have |
| equipment, protecting the head from | | | | good non-ballistic protective qualities, |
| cutting blows with swords, flying | | | | though many do not. Non-ballistic |
| arrows, and low-velocity musketry. They | | | | injuries may be caused by many things, |
| were initially constructed from leather, | | | | including (but not limited to) |
| and then bronze and iron during the | | | | concussive shockwaves from explosions, |
| Bronze and Iron Ages, but soon came to | | | | motor vehicle accidents, or falls. |
| be made entirely from forged steel in | | | | Function and structure |
| many societies after about 950A.D. | | | | Despite various designs and |
| Military use of helmets declined after | | | | requirements, helmets always protect the |
| 1670, and rifled firearms ended their | | | | user's head through a mechanical |
| use by foot soldiers after 1700. By the | | | | energy-absorption process. Therefore, |
| 18th century, cavalry units often wore | | | | their structure and protective capacity |
| steel body cuirasses, and frequently | | | | are altered in high-energy impacts. |
| metal skull protectors under their hats, | | | | Beside their energy-absorption |
| called "secrets". The often-ridiculed | | | | capability, their volume and weight are |
| Prussian spiked helmet, or Pickelhaube, | | | | also important issues, since higher |
| saved many soldiers by diverting | | | | volume and weight increase the injury |
| sideways otherwise mortal sabre blows to | | | | risk for the user's head and neck. |
| the head. Its usefulness was ended by | | | | Classical helmets from the ancient |
| the increased use of heavy artillery | | | | Greeks to today treat the head uniformly |
| during World War I, replaced by the | | | | and are currently tested on rigid |
| German steel helmet, or Stahlhelm, and | | | | headforms. Anatomical helmets adapted to |
| afterwards it was worn merely for | | | | the inner head structure were invented |
| tradition. | | | | by neurosurgeons at the end of the 20th |
| The Napoleonic era saw ornate cavalry | | | | century. Since the materials are |
| helmets reintroduced for cuirassiers and | | | | disposed according to the anatomical |
| dragoons in some armies; they continued | | | | structure of the head, they are smaller |
| to be used by French forces during World | | | | and lighter than the classical helmets. |