Hot Yoga can refer to a flowing, vinyasa style of practice in which the teacher instructs a series of linked poses. The room is usually maintained at a temperature of 95-105 degrees Fahrenheit, with humidity set to around 40%. The poses performed are similar in both hot and traditional yoga, however, the added heat keeps your muscles supple and allows for deeper stretches.
The postures are done in the safe environment of a heated room in order to relieve one's body resistance, without risking injury. The heated body will have an easier time moving into the poses, deepening flexibility and strength. We call this 'the lift'.
As you can imagine, a vigorous yoga session at a high temperature promotes profuse sweating and makes the body very warm. This aids in the detoxification and purification of the body and mind.
In addition, the heat allows for a more meditative state for the practitioner. Very quickly, in a heated practice, the mind learns to focus and become very present with the moment. The mind is stilled. You will find, over time, this mindfulness is taken off the mat, into the everyday, with a new awareness of the mind "chatter" and the judgement that often accompanies it. Soon, you will find you have the decision to not embrace the thoughts, and instead find peace in letting them go. We call this 'the falling away'.
Many people choose to mix-up their yoga practice with both hot classes and traditional classes.