I'm not tired, I'm cooling off my brain

I'm yawning but I'm not tired. My brain is hot. No, seriously. When your brain is warm, you yawn. This is so the air you take in orally can go and cool off your brain.

I did not just make this up.

When Bill first told me this after I was yawning one day, I thought he was crazy. I told him so. Then I saw something about this on some such TV show and Whoa! He wasn't kidding. So now every time I yawn I say, "My brain is hot."

I know that yawning is a signal that your brain isn't getting enough oxygen. Sometimes I yawn a lot so I guess my brain is often quite oxygen-deprived, which explains so much.


According to Wikipedia:

There are a number of theories that attempt to explain why animals and people yawn. It is likely that there are a number of triggers for the behavior. However, there are a few theories that attempt to explain the primary evolutionary reason for the yawn....

One study states that yawning occurs when one's blood contains increased amounts of carbon dioxide and therefore becomes in need of the influx of oxygen (or expulsion of carbon dioxide) that a yawn can provide...

 Another notion states that yawning is the body's way of controlling brain temperature....



Now the next time someone accuses you of being tired when you yawn you can simply say, Au Contraire, I'm cooling off my brain. Unless you crawled in at 3:00 am after a wild night out, then you might just really be tired.