Before migraine. Image 1 of 3. Thermogram of the head (frontal view) of a patient before the onset of a migraine. The colours show temperatures that range from black (cold) through green (normal) to red, yellow and white (hot). Hot spots are seen in the shoulders, while the face and brain are fairly cool, especially the nose (centre). Migraines are severe, repeating headaches, often accompanied by other symptoms such as nausea and photophobia (dislike of bright light). A migraine starts when blood vessels to the head dilate after a period of constriction. For a thermogram sequence showing the onset of a migraine, see images M210/287-289.