Doing exercises in cold temperatures can be beneficial for your body. It can reduce pain and increase your metabolism, allowing you to burn more calories. If you feel cold in your practice space, try drinking a cup of hot water before you start. This will help warm up your body and you can use the heat to help you with your next move.
Adding some lemon to the water can help if you don't like the taste. The main difference between Bikram and hot yoga is that hot yoga studios deviate from the Bikram sequence in some way, so they must use a different name. Regardless of the temperature, both hot yoga and Bikram yoga are designed to relax the mind and improve physical condition.