If your doing bikrim hot yoga for the first time, make sure you drink lots of water before, and after you go, and take a towel, and water bottle ( I fill mine with ice water, and lemon juice, because it gets so hot in the room your water heats up). and don't worry if you feel like you are going to faint or pass out in the room your first time, that is normal, you whole goal the first class is just to stay in the room. And make sure you go twice, just because it kicks your ass the first time, doesn't mean it will be that way the second time, it really does get better after the first time. it is a really great work out, and I am a huge fan.