Candi is right. It was hot! Our room was 105 degrees with high humidity. I thought I would pass out at first, but surprisingly I didn't mind the heat at all after a short while. It was like exercising and getting a nice facial/sauna all at once.
You go through a series of poses that are flow in a certain order and are timed by your teacher. After I was done, I felt tired, but not exhausted, and I felt very relaxed and very stretched out. I highly recommend it if you're looking for something "else" to add to your wellness regimen.