suana

Yes and no. Saunas make you sweat which releases salt and water from the body which is a loss of weight. It works the heart b/c of increased circulation and it can reduce pain and/or swelling to help with workouts and what not. But in general when you re-hydrate yourself after using the sauna you put that water that you lost back into your body. The main gain is the circulation and relaxation. These things can help with weight loss, but a sauna will never be the overall solution to losing the weight itself.

Here's a link about it in better detail:
http://www.3fatchicks.com/the-truth-about-losing-weight-in-the-sauna/