that's what happend to me before as well...
I was doing the Stairmaster for like 10 minutes, then I felt like I was gonna puke and drunk.
I waited for like 15 minutes and didn't get any better, So I had to go home...and while walking towards home I had to stop walking several times and kinda had to go on my knee and hand for few seconds because I felt like I was gonna puke.
if you don't know what stair master is, this is what it looks like...it's meant for cardio but the motion is sort of like squats.
anyways, I went home and had a nap for couple hours and I felt fine.