I ran into this some years ago myself and I remember getting very frustrated trying to get a straight answer from anybody about it. I finally allowed myself to be talked into a shower trim but I was, and remain, unhappy about it. The more so because of the room's low ceiling. Big liability factor here. I'd suggest looking at Harsh Environment industrial fixtures. Voltage and H₂O. Yuck! Oh, and be sure that your client knows not to take a steam bath during a lightning storm!