LPS is also an exogenous pyrogen (fever-inducing substance). That is why IL-1 is called an endogenous pyrogen. Electric matches consist of two parts, a bridgewire and a pyrogen. A pyrogen is a substance that induces fever. If the pyrogen is sufficiently conductive, it can act as the bridgewire as well. Bridgewires dipped in a suitable pyrotechnic composition (pyrogen) are known as electric matches. A pyrogen is defined as any substance that can cause a fever.