In Finland, the sauna is as common as the kitchen – a country of 5.5 million people has around 3 million saunas. On the other side of the ocean, an alternative has gained popularity: the infrared sauna, where panels emit invisible radiation that warms the body without heating the air. The comparison of traditional sauna versus infrared sauna comes up more and more often when choosing a specific form of heat bathing. Find out what clinical data reveal about both methods.
Key facts about Finnish and infrared saunas:
- The Finnish KIHD study showed that men using a sauna 4-7 times a week had a 40% lower risk of all-cause mortality.
- Temperatures differ dramatically – a Finnish sauna operates at 70-100°C, an infrared one at 45-65°C, yet its heat penetrates more deeply.
- The infrared sauna is better tolerated by people who can’t cope with high temperatures and by patients with heart failure.
- The strongest scientific evidence comes from the Finnish sauna, which has existed for thousands of years, while infrared is a 1970s technology.
- Both forms trigger a hormetic response – a beneficial stress that activates the body’s repair mechanisms.
How does a Finnish sauna differ from an infrared sauna?
A Finnish sauna heats the air to 70-100°C using a stove with hot stones, while an infrared sauna emits infrared radiation that warms the body in an ambient temperature of 45-65°C. The Finnish version draws on a tradition reaching back at least 2,000 years, while infrared technology evolved from medical lamps developed in Japan in the 1970s.
How does convective heat work versus infrared radiation?
Convective heat in a Finnish sauna transfers energy through warmed air and water vapour created when stones are splashed with water, so the skin warms rapidly and superficially. Infrared radiation works differently – waves of 3-15 micrometres penetrate the skin by several millimetres and warm the tissues without heating the air.
What health benefits does a Finnish sauna provide?
A Finnish sauna lowers the risk of cardiovascular disease, stroke and all-cause mortality in people who use it regularly. The KIHD study on 2,315 men aged 42-60, published in JAMA Internal Medicine by Laukkanen in 2015, demonstrated a dose-dependent relationship – the more sessions per week, the clearer the protective effect. Regular warming supports heart health, lowers blood pressure and improves vascular elasticity.
Does a sauna reduce the risk of cardiovascular death?
Men using a sauna 4-7 times a week had a 50% lower risk of death from heart disease compared with those visiting once a week. The effect held after adjusting for age, smoking and body mass index. The longer a single session lasted (beyond 19 minutes), the greater the reduction in risk.
Can a sauna protect against dementia?
Data from the Finnish cohort indicate a 66% lower risk of dementia in men using a sauna 4-7 times a week and a 65% lower risk of Alzheimer’s disease compared with infrequent users. The analysis published in Age and Ageing in 2017 included a 20-year follow-up. The topic of brain protection is covered in detail in a separate article.
What does research say about infrared saunas?
An infrared sauna improves vascular endothelial function, lowers blood pressure and increases exercise tolerance in patients with chronic heart failure. The evidence base is smaller than for the Finnish sauna, but several clinical trials over the past two decades have produced consistent findings. Looking at sauna vs infrared sauna health benefits, both forms produce a similar vascular response.
How does infrared affect the heart in patients with heart failure?
In patients with chronic heart failure, regular infrared sessions improve ejection fraction, reduce levels of BNP (a marker of heart failure) and boost exercise capacity. The Japanese Waon therapy protocol is used in some cardiology centres after cardiac assessment. When it comes to infrared sauna vs traditional sauna, the former works better for people sensitive to heat.
How many infrared sessions are needed to see effects?
Most clinical protocols assume 10-20 sessions over 2-4 weeks, with 15 minutes of warming at 60°C followed by 30 minutes of rest under a blanket. When comparing dry sauna vs infrared sauna in terms of session length, Finnish sessions last 10-20 minutes and infrared ones 20-45 minutes.
Which sauna is better – Finnish or infrared?
A Finnish sauna has stronger long-term evidence (20+ years of observation), while an infrared sauna works better for people who struggle with high temperatures. The comparison shows that both methods have their place.
Comparison of Finnish and infrared saunas:
|
Parameter |
Finnish sauna |
Infrared sauna |
|
Temperature |
70-100°C |
45-65°C |
|
Humidity |
10-20% |
Low, dry |
|
Session length |
10-20 minutes |
20-45 minutes |
|
Strength of evidence |
Strong (20+ years) |
Moderate |
Warm baths have a long tradition in cultures that care about health – from Japanese onsens to Alpine spas. The sauna shares many biological mechanisms with them.
Who benefits more from a Finnish sauna?
A Finnish sauna suits healthy people who enjoy temperature contrast and the traditional ritual of splashing the stones. It works well for physically active people seeking post-training recovery. Occasional visits won’t produce a measurable health effect – consistency matters.
When should you choose infrared?
An infrared sauna is the better choice for people sensitive to high temperatures, patients with heart failure (after cardiology consultation) and those with lung conditions. It also suits older adults who don’t tolerate rapid temperature changes.
How often and how long should you use a sauna?
The optimal frequency is 2-4 sessions per week, with cardiovascular benefits appearing even at twice-weekly practice. The sauna is a form of beneficial biological stress – the right dose builds resilience, an excessive one burdens the body. More about the mechanism of good stress in a separate article.
Recommended parameters for a single sauna session:
- Hydration before the session – a glass of water 15-30 minutes before entering.
- Length of the first session – 5-10 minutes for beginners, gradually extending to 15-20 minutes.
- Cooling down between sessions – 5-15 minutes in a cooler environment or a shower.
- A maximum of three sessions per visit, up to 45 minutes of heat in total.
- Replenishing fluids – water with electrolytes restores the sodium lost through sweat.
What temperature and time are optimal?
For a Finnish sauna, the optimal temperature is 80-90°C at 10-20% humidity with sessions of 10-20 minutes, while infrared sessions run 20-30 minutes at 50-60°C. As Dr Rhonda Patrick of Found My Fitness has noted: „A sauna works best when it becomes a regular habit – the effects are cumulative”.
Is a sauna safe for everyone?
A sauna isn’t safe for everyone – people with unstable coronary disease, a recent heart attack, severe hypertension or arrhythmias shouldn’t use one without medical advice. Temporary contraindications include fever, infection, dehydration and alcohol use.
Situations that require caution before a sauna:
- Cardiovascular disease – hypertension, rhythm disorders, coronary artery disease.
- Post-surgical status – wound healing or inflammation at the surgical site.
- Pregnancy – particularly the first trimester, when core body temperature matters for fetal development.
- Alcohol use – increases the risk of dehydration and heart rhythm disturbances.
- Infection or fever – the body is already operating at a raised temperature.
Which is safer for people with heart conditions?
An infrared sauna is usually better tolerated by people with mild cardiac conditions because lower temperatures cause smaller blood pressure swings. People with hypertension or arrhythmia should check with a cardiologist whether a sauna is safe in their specific situation.
Medical note: people with hypertension, arrhythmia or other cardiovascular conditions should consult a cardiologist about sauna use before starting.
FAQ: Most frequently asked questions about saunas and infrared saunas
Is an infrared sauna better than a Finnish one?
Infrared is a gentler alternative for people who can’t cope with high temperatures, while the Finnish sauna has a stronger base of long-term clinical evidence.
How many times a week should you go to a sauna?
For health benefits, 2-4 sessions a week are enough, while more frequent visits (4-7 times) yield a stronger preventive effect in people in good health.
Is a sauna safe for people with high blood pressure?
People with mild, controlled hypertension usually use a sauna safely, but those with severe hypertension or arrhythmia should consult a cardiologist before starting.
How long should you stay in a sauna?
The optimal single session is 10-20 minutes in a Finnish sauna and 20-30 minutes in an infrared one, with 5-15 minutes of cooling between sessions, up to three times.
References:
- Laukkanen, T., et al. (2015). Association between sauna bathing and fatal cardiovascular events and all-cause mortality. JAMA Internal Medicine. https://doi.org/10.1001/jamainternmed.2014.8187
- Laukkanen, T., Kunutsor, S., Kauhanen, J., Laukkanen, J. A. (2017). Sauna bathing is inversely associated with dementia and Alzheimer’s disease in middle-aged Finnish men. Age and Ageing. https://doi.org/10.1093/ageing/afw212
- Tei, C., et al. (2016). Waon therapy for managing chronic heart failure. Journal of Cardiology. https://doi.org/10.1016/j.jjcc.2016.06.004
