I've basically done that since I was a kid. I'd go to school, church, shopping, visit relatives or friends of the family, out on a date as a teen, to work, and start feeling awful for no apparent reason. When I was young I was generally told to "Stop faking it" since there were no real outwardly detectable symptoms and they manifested themselves in many different ways, from headaches to muscle pain, to nausea and gut problems, and combos of all.

By my late teens I figured I must have some odd psychological defect that made me feign illness, but even that didn't seem right since a lot of times it happened when I was genuinely looking forward to being where the ill feelings came on.

By my early 20's I figured out that fresh air and exercise was the sure and only cure. Figuring that out was a boon because sometimes the ill feelings lasted for weeks, but it also helped reinforced my suspicions that it was all psychological since that was all pure fun for me.

Silly me, it turned out to be "chemical sensitivities". Perfumes and solvents are among the leading causes that affect me, and it was a real life changer when I finally understood that.

Church ladies, teen girls, disco dudes, and workplace chemicals, they really do make me sick

I've also learned that not all "fragrances" are the same. Now I can tell with just a whiff if something is "poison" to me, and, since "Chemical Sensitivity" is now acknowledged by the medical community, I can make a graceful escape from overexposure

It wouldn't surprise me one iota to learn that John Muir suffered from the same thing