I talk to a lot of people about yoga, because I really love to talk about yoga. Many people I talk to swear by Bikram and say they won't do any other kind of yoga because other forms don't provide the same detoxifying effects. These folks love the heat and the intensity Bikram brings, and they also claim that it helps them lose more weight.
Hold up here!!! I need to clarify something very important about Bikram yoga. The room you practice in is set to at least 105°F and 40% humidity. This extreme temperature causes the body to sweat profusely to keep you from overheating. Sweating is healthy for the body, and it does help to remove toxins, but it doesn't make you lose weight. The weight you think you've lost from going to a Bikram yoga class is really just water weight because it's so dang hot and you sweat so much. As soon as you go to drink water after class to re-hydrate yourself you'll "gain" all that weight back.
Sorry to burst your bubble people, but sweating doesn't make you lose body weight, and you don't even have to sweat to drop pounds. Calories are what you want to watch out for, and you've got to consume less or burn more if losing weight is your goal.
Fit's Tips: I do not have anything against Bikram yoga, but if you are going to practice in this extreme heat, make sure to drink plenty of water throughout the day before you go to a class. If you don't drink enough, you could suffer from symptoms of dehydration including dizziness, fatigue, and you could even end up fainting.