In 2015, researchers published results from 2,315 middle-aged Finnish men followed for about twenty years. Men who used a traditional sauna four to seven times a week had a 40 percent lower risk of dying from any cause than men who used one once a week. Sudden cardiac death risk dropped 63 percent. Those men sat in wood-lined rooms heated to somewhere around 175 to 212 degrees Fahrenheit, usually throwing water on hot rocks (Laukkanen et al., JAMA Internal Medicine, 2015). There were no infrared panels in that study. Most sauna content online leans on that Finnish cohort, and the saunas involved were the traditional kind.
They are not interchangeable. A traditional Finnish sauna runs high heat and low humidity. Air temperature sits around 175 to 212 Fahrenheit, humidity around 10 to 20 percent, and a session lasts 5 to 20 minutes. Infrared saunas run much cooler, typically 113 to 140 Fahrenheit. The panels warm your body with electromagnetic radiation instead of heating the air around you. That design came from a hospital, not a Finnish lake house.
The origin story explains why the research looks different
In 1965, a Japanese physician named Tadashi Ishikawa received a patent for a ceramic infrared heating system. The original purpose was clinical warming, keeping patients in controlled heat. By the late 1970s and early 1980s, infrared panels had been built into small wooden rooms and sold to the public as saunas. The technology arrived fully formed, then went looking for evidence.
The Finnish sauna ran the opposite direction. It starts centuries back, in smoke saunas where a pile of rocks was heated for hours and the room warmed afterward. Finland has roughly 3.3 million saunas for a population of 5.5 million. UNESCO added Finnish sauna culture to its Intangible Cultural Heritage list in 2020. The research followed the culture, not the other way around. That is why the strongest data involves wood stoves and rocks.
Both rooms work through one mechanism: core body temperature
Both sauna types converge on one biological variable: core body temperature. Raise it enough and cells start producing heat shock proteins, compounds that protect protein structure, reduce inflammatory signaling, and trigger repair pathways. The dose of heat matters more than the heat source.
In a traditional Finnish sauna, heart rate reaches 120 to 150 beats per minute, comparable to moderate paced exercise (Laukkanen et al., Mayo Clinic Proceedings, 2018). Core temperature climbs past 100 Fahrenheit within 10 to 15 minutes. Infrared panels warm skin more gradually. At 120 Fahrenheit, the same core temperature rise takes longer, and some short sessions never reach it. That is the difference most infrared brochures skip.
The marketing line is that infrared penetrates deeper and therefore detoxifies more. The physics does not support that claim. Far infrared radiation penetrates the outer skin by a few millimeters at most. The sensation of deep heat comes from the skin surface warming and the heat conducting inward. That is ordinary heat transfer.
Sweat is sweat. Both sauna types make you sweat, and sweat has been shown to excrete trace amounts of heavy metals including lead, cadmium, and arsenic (Sears et al., Journal of Environmental and Public Health, 2012). That is a measurable process with named compounds, not a vague cleanse. Total sweat volume tends to be higher in a traditional sauna at 175 degrees than in an infrared session at 120 degrees, so the traditional session moves more liquid through the skin in less time.
Where the long-term evidence divides
Traditional sauna health claims rest on unusually large cohort data. The same Finnish research group published a 2017 paper showing a 66 percent lower risk of dementia and Alzheimer's disease in men who sauna four to seven times weekly compared with once weekly (Laukkanen et al., Age and Ageing, 2017). A 2018 study reported 61 percent lower stroke risk with the same frequency (Kunutsor et al., Neurology, 2018). The dose-response relationship is consistent: more sessions per week, better outcomes.
Infrared sauna evidence is thinner but not absent. Waon therapy, a Japanese protocol using a 140 Fahrenheit far infrared room for 15 minutes followed by 30 minutes of resting while wrapped in blankets, improves endothelial function and symptoms in patients with chronic heart failure (Miyata and Tei, Circulation Journal, 2010). A four week infrared sauna program reduced pain and stiffness in rheumatoid arthritis and ankylosing spondylitis patients, with benefits still present four weeks after treatment ended (Oosterveld et al., Clinical Rheumatology, 2009). Those are real clinical signals. They are smaller, shorter, and disease-specific. No infrared sauna study has tracked thousands of healthy men for twenty years the way the Finnish cohort studies have.
What this means for men: cardiovascular risk and the fertility question
Cardiovascular disease is the leading cause of death in men across most Western countries. The strongest sauna data on cardiovascular mortality comes from traditional sauna. If that outcome matters to you, the Finnish protocol has the most evidence behind it.
- Temperature: 175 to 212 Fahrenheit
- Duration: 10 to 20 minutes per session
- Frequency: at least 2 to 3 times per week, with 4 to 7 showing the strongest results
- Cooling: take breaks between rounds to let heart rate settle
Then there is the fertility question, which matters to a lot of men who sauna regularly. Sauna level heat temporarily lowers sperm count and can worsen morphology. The effect reverses once the heat exposure stops, because sperm production needs the testicles a few degrees cooler than core body temperature (Garolla et al., Human Reproduction, 2013). Stopping regular wet heat lets semen parameters recover (Shefi et al., Fertility and Sterility, 2007). Infrared rooms run cooler than traditional saunas, but the body still heats from the inside during a session. No head to head study proves either sauna type is gentler on sperm production. The honest position is that any session hot enough to raise core temperature can temporarily affect sperm. A single session does not crash testosterone, and the long term effect of regular heat on circulating testosterone has not been settled by large trials. If you are actively working on fertility, a doctor can run the relevant labs and give individualized guidance.
How to choose without overthinking
If you want the largest body of long-term human data, traditional Finnish sauna is the answer. The dose that keeps showing up in the cohort studies is at least two to three sessions per week, with four to seven sessions producing the strongest results. Heat, duration, frequency. That is the order of importance.
If you have a condition where gentler heat is more tolerable, such as heart failure or heat sensitivity, infrared at 120 to 140 Fahrenheit for 20 to 30 minutes is the setting with clinical signals in those populations. A quick 15 minute session at 120 degrees is unlikely to reproduce what the Finnish cohort experienced. If infrared is your only option, longer sessions or more frequent ones are the usual way to compensate for the lower temperature.
The mistake to avoid is blending the two evidence bases and pretending they are one thing. The Finnish men who drove the 40 percent all-cause mortality figure were not sitting in 120 degree rooms waiting for panels to warm their skin. They were throwing water on hot rocks.
This content is for educational purposes only and is not medical advice. Oakman products are designed for physical comfort and cooling. They make no claims about fertility, sperm quality, or hormone levels. Consult a healthcare professional for personalized advice.
Frequently asked questions
does infrared sauna get hot enough for the same benefits
Infrared saunas run at 113 to 140 Fahrenheit, much cooler than a traditional Finnish sauna at 175 to 212 Fahrenheit. The lower temperature means core body temperature rises more slowly, and short sessions may never reach the point where heat shock proteins ramp up. Longer sessions or more frequent use can help close that gap.
which sauna is better for heart health
Traditional Finnish sauna has the strongest cardiovascular evidence. The 2015 Finnish cohort study of 2,315 men linked four to seven weekly sessions to a 40 percent lower risk of all-cause death and a 63 percent lower risk of sudden cardiac death. Infrared sauna has smaller, disease-specific clinical signals, but no long-term healthy-population data like that.
does sauna use lower testosterone or affect fertility
Sauna level heat temporarily lowers sperm count and can worsen morphology, but the effect reverses once regular heat exposure stops. A single session does not crash testosterone, and the long term effect of regular sauna use on circulating testosterone has not been settled by large trials. If fertility is a current concern, talk to a doctor before making sauna a habit.
how often should men use a traditional sauna
The Finnish cohort data showed the strongest results at four to seven sessions per week. At a minimum, two to three sessions per week consistently appears in the studies. Each session should run 10 to 20 minutes at 175 Fahrenheit or higher, with cooling breaks between rounds.