Sauna has been used for generations as a place to warm the body, slow down, and recover.
Today, researchers are also studying what regular heat exposure may do inside the body — from circulation and cardiovascular function to respiratory health, recovery, and overall well-being.
This guide breaks down what we currently know about traditional sauna and passive heat therapy.
Traditional sauna exposes the body to a high-temperature environment, typically using heated stones and dry air.
Unlike exercise, your muscles are not doing the work — but your body still has to respond to the heat.
As your body temperature rises, your cardiovascular and thermoregulatory systems begin working to release heat and maintain a safe internal temperature.
That physiological response is one reason researchers are interested in sauna as a form of passive heat therapy.
Sitting in a hot sauna creates a temporary physiological stress. Your body responds almost immediately.
Heat places additional demand on the cardiovascular system as the body works to move warm blood toward the skin.
Heat promotes vasodilation, increasing blood flow toward the skin and helping the body release heat.
Sweating is one of the body’s primary cooling mechanisms.
More blood is directed toward the skin while the cardiovascular system adapts to the heat load.
These responses are temporary, but repeated exposure is being studied for the adaptations that may occur over time.
Sauna research has grown significantly, but the strength of the evidence varies depending on the health outcome being studied. Some findings come from controlled clinical trials, while others come from observational studies that follow people for many years.
Cardiovascular health is one of the most studied areas of traditional sauna research.
A well-known Finnish prospective study followed more than 2,000 middle-aged men and found that greater sauna frequency was associated with lower rates of sudden cardiac death, fatal cardiovascular disease, and all-cause mortality.
This does not prove that sauna alone prevented those outcomes. People who sauna frequently may also differ in exercise, lifestyle, social habits, and other health factors.
A later randomized controlled trial found that participants who added a 15-minute post-exercise sauna to an eight-week exercise program had greater improvements in systolic blood pressure, cardiorespiratory fitness, and total cholesterol compared with exercise alone.
Heat causes blood vessels to dilate, making vascular function and blood pressure logical areas of study.
Observational research has associated more frequent sauna bathing with a lower future risk of hypertension, and some intervention studies have reported improvements in cardiovascular measures.
However, results are not universal. That is an important reminder that sauna research is still evolving, and not every population or protocol produces the same results.
One of the most noticeable effects of sauna isn’t something you need a laboratory to recognize: many people simply feel different when they walk out.
Heat initially activates systems involved in managing physical stress. After the heat exposure ends and the body begins cooling, many people experience a pronounced sense of relaxation.
Athletes and active adults often use sauna after training because heat increases circulation and provides a passive period of rest.
There is growing research around heat exposure, exercise adaptation, and cardiovascular conditioning, but claims that sauna directly “heals muscles,” eliminates inflammation, or dramatically accelerates injury recovery go beyond what current research can confidently say.
In Finnish cohort research, greater sauna frequency has been associated with reduced risk of certain acute and chronic respiratory conditions.
These findings are associations rather than proof that sauna prevents respiratory illness.
Heat exposure is also being studied at the cellular level. Researchers are interested in how repeated heat stress may influence protective cellular pathways, inflammatory signaling, metabolic function, and adaptations to physiological stress.
This is an exciting area of research, but also an area where wellness marketing can get ahead of the evidence. Sauna should not be presented as a treatment for metabolic disease.
For many healthy adults, a traditional sauna session often falls somewhere around 10–20 minutes at a time, followed by cooling and hydration.
Longer is not automatically better.
Finnish observational research often grouped sauna use into once weekly, two to three times weekly, and four to seven times weekly.
Consistency and tolerance matter more than chasing a number.
Both traditional and infrared saunas use heat, but they create that heat differently.
Traditional sauna heats the room around you, typically using a sauna heater and heated stones.
Infrared sauna uses infrared energy to transfer heat more directly toward the body and generally operates at a lower air temperature.
Most people using sauna for relaxation and recovery prefer it after training.
Exercising already increases body temperature and cardiovascular demand, so adding sauna afterward creates a natural transition from effort into recovery.
Alternating heat and cold is commonly called contrast therapy.
Heat encourages vasodilation and raises skin temperature, while cold produces a rapid cooling response and peripheral vasoconstriction.
Importantly, research on sauna alone should not automatically be used to make claims about sauna-and-cold protocols. Contrast therapy is its own area of research.
Sauna is generally well tolerated by many healthy adults, but heat exposure is not appropriate for everyone.
Talk with a qualified healthcare professional before sauna use if you have significant cardiovascular disease, problems regulating blood pressure, are pregnant, take medications that affect hydration or cardiovascular response, or have another condition that may affect heat tolerance.
Most importantly, listen to your body. Lightheadedness, nausea, unusual weakness, chest discomfort, or feeling unwell are reasons to leave the heat.
At Ash & Sage Sauna Spa in Melissa, Texas, traditional sauna is part of a self-guided recovery experience designed to let you slow down, listen to your body, and move at your own pace.
Our Open Suite combines traditional sauna with cold plunge, hot therapy, and red light, allowing you to create a recovery ritual that works for you.
You don’t have to be an athlete. You don’t have to know the perfect protocol. And you don’t have to turn recovery into another thing to accomplish.
Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events
Laukkanen T, et al. · JAMA Internal Medicine · 2015
Read on PubMed →Effects of Regular Sauna Bathing in Conjunction With Exercise on Cardiovascular Function: A Multi-Arm, Randomized Controlled Trial
Lee E, et al. · American Journal of Physiology · 2022
Read on PubMed →Sauna Bathing and Incident Hypertension: A Prospective Cohort Study
Zaccardi F, et al. · American Journal of Hypertension · 2017
Read on PubMed →Sauna Bathing Reduces the Risk of Respiratory Diseases: A Long-Term Prospective Cohort Study
Kunutsor SK, et al. · European Journal of Epidemiology · 2017
Read on PubMed →Create your own recovery ritual with traditional sauna, cold plunge, hot therapy, and red light.
EXPLORE SESSIONS & PRICINGThis article is for general educational purposes only and is not medical advice. Sauna research continues to evolve, and individual responses to heat exposure vary.