There is provided a forehead temperature measurement system including an image sensor, a thermal sensor and a processor. The image sensor is used to output an image frame. The thermal sensor is used to output a thermal image. The processor is used to determine a forehead region in the image frame, map the forehead region to the thermal image and identify a forehead temperature according to a forehead mapped region in the thermal image. The processor further calibrates or compensates the forehead temperature according to an area. of the forehead region.