An integrated circuit temperature sensor includes a sensor to determine whether the integrated circuit is currently exposed to a relatively low or high temperature. A measured voltage across the base-emitter of a bipolar transistor is selected if the sensor indicates exposure to the relatively low temperature or, a measured delta voltage across the base-emitter of the bipolar transistor is selected if the sensor indicates exposure to the relatively high temperature. The voltage across the base-emitter is compared against a first reference for determining exposure to a too cold condition or the selected measured delta voltage across the base-emitter is compared against a second reference for determining exposure to a too hot condition. In a test mode, the measured delta voltage across the base-emitter and/or the measured voltage across the base-emitter are scaled.