I'm getting over the same lousy crap that everyone else has had here lately...the profusely leaking brain lubricants, the sneezing and pounding head. But the good news is it's just a bad cold and not the ever-dreaded flu. I got REALLY sick about 4 years back and I was recalling that fun time this afternoon as I rode. It was one of those days where the air temp is borderline, maybe about 40+ degrees but not what you'd call cold at all. I thought it was crazy at the time, but I had gone out for a spin and didn't bother with a face mask or a neck gaiter or anything and by the time I got back my lungs felt like they were literally on fire, yet icy, while the rest of me had been totally comfortable. I hadn't had a cold or anything prior to this, so I just figured they had gotten chilled somehow. Within two days I was flat on my back and bringing up some truly colorful stuff, and I was grounded from riding for over a week and a half. Talk about a sanity-tester! Was this just because of the chilly air or is it possible I was coming down with something and it just became apparent after I rode?
I always wear a gaiter now when the temps fall below 50, even if I just keep it around my collar and not over my mouth, but at least it's there.