Abstract: A safety device for preventing deleterious overheating of an electrical lighter such as used in motor vehicles provides a short circuit in the electrical power supply circuit to the lighter upon occurrence of a dangerous overheating condition so that a circuit breaker in the circuit is actuated to deenergize the lighter. The safety device includes a pair of electrical contacts on the lighter socket separated by a thermoplastic insulating member in heat exchange relationship with the socket and being composed of a material which has a softening point above the normal operating temperature of the lighter but below the temperature at which thermal damage may occur in the vicinity of the lighter when overheating occurs. One of the contacts is spring biased toward the other and the softening of the insulating member allows the contacts to electrically engage under the force of the spring bias to establish a short circuit for actuating the circuit breaker.