Carrie,
Wizard is such a kidder. He meant BS-proof vest (and boots) as that substance is in great quantity on this forum. ;-)
The clothing requirement at wilderness hot springs is often birthday suits, but clothing optional is the unofficial policy, which means no one can tell you that you should be dressed, or undressed. I've never been to the springs on a bad day and February visits are often quite nice, but come back in the early summer, for that time is truly the best.
Have a great visit and tell us how it went.