Hi there,   There are so many things that can trigger an asthma attack, and every person can be slightly different. We do know that extremes in temperatures can trigger asthma symptoms. So, in winter, when air is cold & dry, asthma attacks can occur. Same thing in high summer, when air is hot & humid. I suspect the shower is mimicking a summer day for you.   Alternatively, it's possible there are mold spores growing in the room where you are showering. Mold is a powerful and common asthma trigger. It may not be easily visible. Vigorous cleaning with a antifungal solution (preferably NOT by you) should help in that case.   Are you taking a daily or twice daily controller medicine for your asthma? This should help prevent attacks, even if you are exposed to triggers. Also, you should have a rescue, or quick-relief inhaler, that will help you quickly deal with asthma attacks, should they occur.   You may want to talk with your doctor about your asthma care plan, to help get a handle on what's happening.   To your health, Kathi