Ghostly Things

I have heard of "Cold Spots" before on shows about the paranormal and ghost hunting but i've never run across it before.
But a couple of nights ago as i was getting into bed i felt the air around me get very cold (mind you this was before we got the current cold snap here and the house was warm), i just felt it was something different and i wonder what or whom it was, the cold spot only lasted a few seconds.
Maybe it was some weird draft but i feel it wasn't.