Been ill for the past week so haven't posted.  Sorry folks, especially Nick.

Still, here we go again.

Today's interesting fact has to do with why we yawn.

There have been many theories as to why we yawn, from threatening possible enemies, to increasing the oxygen we get into our blood, to helping us to wake up.  But lately someone looked at the roof of our mouths with specialist equipment and watched what happens to blood flow, temperature and air flow when we yawn.

The examination of the resultant data suggests that while some of the other suggestions may have some validity, perhaps the biggest reason we yawn is to cool our brains.

The soft palette at the top of our mouths are full of blood vessels that can be used to transfer warmth from the brain into our breath as we breathe out and then colder air coming into our lungs during the yawn then reduces the blood temperature further which then further cools the brain.

And this also explains why we get brain freezes when we accidentally place ice cold foods or drinks on that soft pallet.