The heater shield or heater-shaped shield is a form of European medieval shield, developing from the early medievalkite shield in the late 12th century as depicted in the great seal of Richard I and John. The term is a neologism, created by Victorian antiquarians due to the shape's resemblance to a clothes iron. Smaller thanthe kite shield, it was more manageable and could be used either mounted or on foot. From the 15th century, it evolved into highly specialized jousting shields, often containing a bouche, a notch or "mouth" for the lance to pass through. As plate armor began to cover more and more of the body, the shield grew correspondingly smaller, until by the mid 14th century, it was hardly seen at all outside of tournaments. Heater shields were typically made from thinwood overlaid with leather. However, they were often also made of metal or like materials, or were made of wood braced with metals such as steel or iron. Heater shields often featured a strap, called a guige, for the shield to be slung over the back when not in use. Some shields, such as that of Edward, the Black Prince from his tomb in Canterbury Cathedral, incorporated additional layers of gesso, canvas, and/or parchment. The heater shield was used by almost every class of society in medieval Europe, from knights to typical soldiers. This design lent itself to being relatively inexpensive and easy to make. It was relatively lightweight compared to other similar shields at the time such as the kite shield, being easy to move around during both mounted and on-foot combat, and had a fairly high amount of surface area, making for a solid defense. However, this style of shield was not without its flaws. When using a heater shield properly, the legs are left almost entirely unprotected, although this disadvantage can be eliminated by moving away from an opponent. "When a sword flies for your leg Make a downward blow to his face or around to his throat: His arms will be wasted more quickly than his head, Because the distance is manifest for a shorter time." Unfortunately, there is very little documentation remaining in the world regarding the proper use of a heater shield with a sword or any other weapon. Heater shields were often used for heraldic display, or display of the coat of arms of the wielder. This lent itself to the relatively wide surface area of the shield and its shape, which made it excellently suited for display.
