An electrical device includes a system circuit for performing a function, a dedicated power supply, and a hermetically sealed housing. The device includes a thermal switch which is electrically connected between the system circuit and the power supply and is switchable between an open position wherein the system circuit is electrically isolated from the power supply and receives no power therefrom and a closed position wherein the system circuit is electrically connected to the power supply and receives power therefrom. The thermal switch switches from its closed position to its open position in response to the temperature within the housing rising to a predetermined switch-open temperature value and thereafter switches from its open to its closed position in response to the temperature within the housing cooling to a switch-closed temperature value. The electrical components of a device are automatically protected from thermal damage during sterilization.
