An apparatus and method for testing thermal switches is disclosed including modulating the temperature of a receiver in thermal contact with a thermal switch at a first rate within a range containing the nominal switch temperature of the thermal switch. A first temperature at which the switch changes state is recorded. The temperature is then modulated at a second rate and a second temperature at which the switch again changes state is recorded. The temperature may be modulated at a third rate slower than the second rate to determine a third temperature. The first, second, and third switch temperatures are then processed and output to an operator. The first, second, and third rates may be determined according to an exponentially decreasing function.