Man's body temperature. Thermogram of the body of a standing naked man, in front view. A thermogram records the infrared radiation that is given off by the skin as a measure of its temperature. The colours represent temperature differences: from white (hottest) through red, yellow, green, light blue, dark blue, to purple and black (coolest). Skin temperature may reflect the volume of blood supply across parts of the body, with the extremities being cooler such as the nose, fingers and toes. A thermogram can also highlight a variety of circulatory dysfunctions, inflammation and occasionally tumours.