Yawning cools the brain, new study says 0
Yawning cools the brain, new study says (Fotolia)
Yawning helps cool your brain, but that only works when it is just the right temperature, a new study suggests.
The researchers from the State University of New York and the University of Vienna looked at how often people yawned in Austria in the summer and winter, and compared it to yawners in Arizona.
They found people in Vienna yawned more in the summer than the winter, but the opposite was true in Arizona.
The researchers said people tended to yawn more when the temperature hovered around 20 C.
That's because yawning did nothing to cool the brain when temperatures were warmer than that, and they warned it could be "harmful" to yawn in freezing weather.
Cooling the brain improves a person's mental efficiency, the researchers said.
The study has been published online in the journal Physiology and Behavior.