Hi mcroy,
What I'd do is rmove the cover (if possibl some phones can't easily do this) remove the battery and sim. Dry as it off much as you can and leave in a warm place like an airing cupboard overnight. This should get rid of most of the moisture, but if ther's still condensation on the inside of the screen leave it for another few hours.
If you are very unlucky and water gets into the LCD display it'll be ruined for good, so you'll need to get that replaced. Hope it all goes well