Getting too hot? Sitting by the fire for too long? Try yawning... apparently...
According to researchers from Yale University and the University of Maryland, YAWNING may act to cool the brain when it gets too hot. Yawning opes up the sinuses located to the left and right of the nose, so that letting air into these places would reduce brain temperature.
Researchers argue that yawining is a symptom of conditions that cause an increase in the brain or core temperature. It is true that fits of yawning have been noticed to precede epileptic seisures and migraines.
Studies done in mice do demonstrate that the brains of mice increased in temperature just before a yawn and decreased directly after. A potential cause for this is that the mucus in the sinuses may constantly evaporate, and thus cool the surrounding blood vessels and cerebrospinal fluid. Bringing in new air into the sinues would speed up this process, cooling the brain.
Now I am going to refuse to stifle that yawn, whether it happens in class, or in a job interview... or when meeting the Queen. I do not want to overheat my brain.