A yawn can cool your brain
It turns out yawning might not be a sign of fatigue or boredom.
It could be the brain’s way of cooling off.
Researchers have found people yawn almost twice as much in the winter, when their body temperature was higher than the air around them.
When your brain is working overtime, the theory is that yawning lets cool air rush in and bring your brain back down to an optimal temperature.
