A temperature sensitive indicator 24 in the form of a label or decal is affixed to the outside of a thermal switch 20. The temperature sensitive label provides a permanent record of the temperature limits exposed to the thermal switch. The temperature sensitive material changes colors when the thermal switch is exposed to its predetermined temperature limit. The changed color provides a quick and clear indication of an event that caused switch activation. The color indication on the outside surface of the switch also provides a visual indication that is easy to acquire and inspect without the need to have physical access to the switch itself.