My sister and I went to a hot-springs resort in New Mexico for three days several years ago. Ahhhhh. It had several different kinds of water that occurred naturally, some hot enough to cook your flesh, some just hot, some warm, some cool. There was also a natural mud bath, which was interesting. There was a huge body-temperature pool that was open til midnight. Floating in that pool, looking at at a billion stars.....sublime.
Same sister and I were at a hot springs resort in Costa Rica that had pools cascading down the mountain. At the top it was steaming hot and each pool got cooler as the water ran down. We'd start at the top, work our way down and then back up again.
There's nothing I'd rather do than to go spend a week at a hot springs resort and just soak the achy old body again in healing waters.