Tonight I was preparing poblano peppers for baking (with stuffing). I wore gloves to protect my hands from the oils, and (after a recent case where that wasn't enough) I also ran the vent fan. However, after cutting and seeding the peppers (at the counter next to, but not directly under, the vent fan) and being very careful not to touch any other part of my body, I found my cheeks were still starting to sting. I assume this must have been from vapors; I know for a fact that I did not touch my face with my hands. If this happened with poblanos (granted, one of them turned out to be abnormally hot), I'd be afraid to try working with a really hot pepper.
How did my face pick up pepper heat, and how can I prevent this problem in the future? Did running the vent fan make it worse (by causing vapors to move through the air)? Is this the sort of thing only safely done outdoors on a calm day?
If answers involve some sort of face covering, please note that I must wear glasses.