Ringodoggie you may indeed have solved the mystery. The Airizer Air was brand new, though I did follow the recommendation given at the FC forum, to run a couple of burn cycles before inhaling from a new vaporizer, to get rid of the plastic smell, and to burn of any oil residue left over from the manufacturing process. Could be I did not repeat those burn cycles enough times to properly vent off all the factory gases, in my haste to try vaping for the first time ever.
Yardgrazer I do indeed have family members that suffer from asthma, which is hereditary, even though I have never been diagnosed with asthma myself. That said, the shortness of breath I experienced on that day was very similar to a symptom of asthma, even though that was the first and only time thus far, that I suffered that way.
All told, I find that using a bubbler has worked for me, so I always go to the trouble of hooking one up. I have never used a vape without a bubbler since that incident. Playing it safe, I guess, in the absence of a confirmed reason for that episode.
I feel more like I do now, than I did before I made this observation.