Yeah, people really don't try to put themselves in someone else's shoes. With my kin, you'd think seeing me languishing and sick all the time, even hospitalized, would make a difference. They just won't connect the dots.
A lot of exposure issues don't bring on immediate responses. For example, air fresheners or scented candles. Most of the time, I may seem fine for the hour or two I'm exposed. However, I will be gasping for my inhaler soon enough. Because it's half a day before I need my inhaler, they say it's just having asthma. The thing is, I needed it every single time I went to their homes. I never need it in my own.
Thankfully, my husband and son get it. My best friend (and my son's godmother) gets it too. When I visit her home, she makes every effort to eliminate those things days before I arrive.