I had one on the weekend - I always do when I saty with the ILs, because we don't have one here in brissy. Didn't stay in long, kept it to 34deg, rest of the room cold, drink of cold water.

Maybe I shouldn't have, but I wanted one so bad.
Nah, it's fine! They even recommend baths in the preggy books and so do a lot of doctors for that matter. It's a brilliant way to relax and they are a natural pain relief - perfect for all those preggy pains!