If your bags are not going through to your next flight, store them at the baggage storage place at the airport. It's just a few Euros. Then go downstairs and hop on the subway. Take a short ride to Konstablerwache station. A five minute walk from there will bring you to the gay Golden Gate sauna, where you can take a refreshing shower and relax in the steam room, get some rest, and if you're up to it then maybe also get laid. Don't forget to head back to the airport 2 hours before your next flight... at about 15 Euro, it's a much better deal than a Sheraton.