Thermogram of a man holding his left arm above his head, showing the heat of his armpit (white) due to the proximity of blood vessels to the skin surface. The loss of heat from the armpits is one of the human body's means of temperature regulation. Note also the man's cold nose and hair (black). Skin temperature is colour coded from white (hottest), through to black (coldest), with a difference of 1 degree Centigrade between each colour. The thermogram was made in a room at a temperature of 10 degrees C.