Your soft tissues are softer and more relaxed, allowing a safer deeper stretching to occur. The profuse sweating both detoxifies the body and also produces a natural cooling mechanism to help prevent the body from overheating
This environment raises the heart rate to produce a cardiovascular workout. The heat also lowers the viscosity (thickness) of the blood, allowing it to flow more easily and deeply into bodily tissues and organs to help in healing injured areas.
Your immune function is boosted.
The focus developed in this environment strengthens your discipline, determination and power of concentration.
During your first class, the heat is usually a significant distraction! However, over time, you will begin to love the heat and will only notice the heat if the room is not hot enough!
This is not unusual. Feelings of dizziness and nausea are part of the process of acclimatising to the hot room and may also be a result of releasing toxins. For some people, they will feel this straight away, for some it might come up in the second, third or fourth class. If this occurs, whether you are a beginner or more experienced, try kneeling down in Japanese style first. If the feelings don't pass, then lie down flat on your back. Once you feel better and you are ready to rejoin the class, get up slowly. Rest as much as you need to and always make it your goal to stay present in the room for the full 90 minute class. You don't have to complete every posture to gain benefit from this practice. Ensure that you drink lots of water after your class.