From Finland, to the United States, to Russia, and Japan, sauna bathing has gained considerable popularity. The heat in a sauna, often around 180-200 degrees fahrenheit, envelopes the body, causing sweat production to increase. Many sauna bathers will tell you it produces the ultimate “clean” feeling. Others will tell you it enhances their well being. And others will swear it’s their secret to health. While anecdotal testimonies do have some merit, many folks are interested in what the structured research says about sauna bathing, so let’s take a look.
1. Sauna Bathing Promotes Chemical and Toxic Metal Cleansing
Unfortunately, pollution has permeated our entire world and our environment is contaminated with synthetic chemicals. Test nearly any person alive and you’ll find detectable levels of man-made chemicals in their body. Most of this toxic trash is fat-soluble, meaning it stays in the body where it has access to all organs and even the blood-brain and placental barriers.
Sweating, however, promotes cleansing and should absolutely be considered for detoxification of toxins, including arsenic, cadmium, lead, mercury, copper, nickel, manganese, sodium, chloride, ammonia, and urea.   
In 1978, L. Ron Hubbard (the Scientology guy) constructed a protocol to promote the broad elimination of chemicals from the body. The regimen included exercise, sauna bathing, and nutritional support; it’s been adopted by medical practices in over 20 countries.  Additionally, the Southwest College of Naturopathic Medicine in Tempe Arizona has reported that regular sauna use helps to mobilize fat-soluble toxins. 
For readers who are not content with the assertions of a Scientologist or a bunch of hippies in the desert… Okay, what about the University of Southern California School of Medicine?
Researchers there reported of firemen who had been exposed to PCBs and experienced neurobehavioral impairments as a result. After a three week detoxification protocol that included a dietary regimen, exercise, and sauna, they experienced significant improvement. 
Similarly, the St. Joseph’s Health Centre in Toronto reported of a patient who had experienced low-level exposure to toxic solvents for over twenty years. As a complementary therapy, sauna bathing helped to balance the patient’s condition and she was able to discontinue all medications that had been previously prescribed for her symptoms. 
2. Sauna Bathing Should Not Be Mixed With Medication or Chemicals
Although sauna bathing has its benefits, sauna heat does exert a stressor effect on your body. It’s best not to mix it with other stressors, such as alcohol or drugs. Unfortunately, this practice is far more common than it should be, and is especially risky.
Certain medications, like blood pressure medication, may cause low blood pressure after bathing.  However, most of the time, problems result from combining alcohol consumption with sauna use. That has been linked to high blood pressure, arrhythmia, and sudden death.  In that regard, if we need to point fingers, most often the problem is middle aged men who drink in the sauna, pass out, and experience burns or death. 
3. Sauna Bathing Promotes Mental Health
Ask most sauna bathers what they like most about the sauna and they’ll tell you how relaxing it is — mentally and physically. Research supports this claim. According to the Tampere University Hospital in Finland, sauna use may help reduce stress.  This assertion has been backed by Japanese researchers who found similar results, reporting that sauna bathing improves tension, mood, anger, fatigue, and confusion. 
4. Sauna Bathing May Not Boost Athletic Performance
Competing in a desert marathon? Don’t look to the sauna to help you adapt to the hot climate. The Finnish Defense Forces explicitly advise against this practice and recommends that athletes ought not look to the sauna to enhance their performance. However, they do suggest that it’s an excellent way for athletes to cleanse their body, refresh their mind, and relax. 
Other research has even shown a negative effect immediately following sauna use. The Department of Physiology at the University of Granada found that sauna-induced dehydration significantly decreases leg strength in women.  It doesn’t only affect women. In 2002, researchers at the University of Sydney evaluated ten athletic men and found that their muscular endurance decreased significantly after sauna exposure. 
Note that both of these studies indicate that strength reductions were observed after sauna bathing, which itself is very similar to exercise and leads to similar temporary fatigue. Which means that maybe…