I too have been in the cloud of fumes and basically felt like I pepper sprayed myself. Not pleasant - eyes watering, throat constricted, short, shallow breaths.
It also tends to mess with my respratory system - many many times I've made a full 2-3 gallon batch at home and found myself constantly clearing my throat, sinus headache, sneezing like crazy. And that's with good ventilation!
One thing is for certain - capsaicin is no joke.