An improved method and apparatus for setting a trip-point temperature value for detection of an over-temperature condition in a chip when a reading from a main temperature sensor exceeds the trip-point temperature value. In one embodiment, the trip-point temperature value is set to a known temperature limit value offset by a temperature difference, .DELTA.T. .DELTA.T is calculated by taking the difference between a reading of the main temperature sensor and a reading of another temperature sensor, remote from the main temperature sensor, while a heat-generating circuit is enabled. The main temperature sensor is distal from heat-generating circuit on the chip and the remote temperature sensor is proximate the heat-generating circuit. For multiple heat-generating circuits on the chip, a .DELTA.T is determined for each of the heat-generating circuits, and the largest .DELTA.T is used to calculate the trip-point temperature value. Advantageously, the largest .DELTA.T determination may be done only once.