The temperature in the Tepidarium is around 37 to 41 degrees. Through this your body is feeling a healthy fever which is strengthening your immune system. In opposite to real fever the generated fever in the Tepidarium is relaxing and strengthening your circulation.
Even after a sickness the Tepidarium can be used because it is slowly building your immune system. Also for the prevention of common cold the Tepidarium is useful.
In the Tepidarium you can relax 30 minutes and longer. Ideally you go to the Tepidarium 2 - 3 times a week.