Saunas are relaxing and stress relieving. Those with muscle aches or arthritis may find that the heat relaxes muscles and relieves pain and inflammation. Some asthma patients find that the heat dilates air passageways of the lung and facilitates breathing. A number of doctors will recommend the use of a hot tub or hydrotherapy in order to relieve pain from different parts of the body for those with illnesses or conditions that may be worsened by sauna use.
Saunas do not cure the common cold, but they may help to alleviate congestion and speed recovery time. The body's core temperature usually rises 1-2 degrees while in the sauna, thus imitating a slight fever. The sauna could be considered to follow the old adage "starve a cold, feed a fever." The regular use of a sauna may decrease the likelihood of getting a cold in the first place.
Saunas are also good for your skin – they increase the blood flow to the skin and induces sweating. Adults sweat about 2 lbs of water per hour on average in a sauna. A good sweat removes dirt and grime from pores and gives the skin a healthy glow. It is important, however, to wash your skin with cold water after relaxing in a sauna. The heat from the sauna will cause the pores to close and any dirt or grime remaining in them after you get out will be trapped under the skin.
The cardiovascular system also gets a work out as the heart must pump harder and faster to move blood to the surface for heat exchange. Heart rate may increase from 72 beats per minute on average to 100-150 beats per minute.
A normal heart can handle these stresses, but those with heart trouble should seek a doctor's advice before using a sauna. The elderly and those with diabetes or circulatory conditions should check with their doctor prior to sauna use as well.
Heavy meals and alcohol should be avoided prior to entering the sauna. Digestion requires a good deal of blood flow to the gastrointestinal system and therefore limits the heat exchange capability of the blood vascular system.
As a depressant, alcohol can dull the senses so that you don't realize how hot you are getting or may cause you to fall asleep. Drinking water in the sauna is not a bad idea as it replaces fluids lost via sweating.