Yes, ickivicki, it's happened to me twice. Once at my bf's frat party (how embarrassing! ) and once when I worked at a tie-dye shop. The first time, I felt exactly like you did and my blood pressure was sky high besides. They almost took me to the ER. I was really scared because I'd been smoking for 2 years when it happened.

The second time, I was dying blue shirts and I DID pass out, right in the blue dye. Lovely. It was the same experience. Luckily, the place was owned by 2 really cool guys who took care of me and drove me home. This was the last time it happened to me and it hasn't happened again in 6 years.

I don't know why it happens. I don't think it has anything to do with cigs because I don't smoke them. Sorry that I can't help you out but at least I can say I know how you feel.