Yeah it is actually beneficial for your health, although it is pretty much pointless in the summer. The sauna helps you sweat; ridding your body of toxins... it also opens up your pores and has been known to make people's skin glow, as well as mildly reduce physical aging (when taking saunas everyday). It's also soothing... but yes, it does dehydrate you, due to the sweating. So, make sure to bring a bottle of water with you into the sauna