Cool Draft=I've Gotta Yawn

This is obviously a takeoff on the I’m Cold=I’ve Gotta Pee thread but I’ve been wondering about this for a few years now. It doesn’t doesn’t matter if I’m indoors or out, though 9 times out of 10, I’m indoors. When I feel a cool draft, I automatically start yawning. It doesn’t seem to be the coolness itself because I actually prefer being a little cool over being a little warm, and in a cool room without a draft, this doesn’t happen. I’m not tired or bored either when this starts. I don’t know anyone else this happens to. What is my body trying to accomplish? It’s only been 3 or 4 years that I’ve noticed this. Is it something to do with ageing? I’m in my mid 40’s.