The wellness community and industry are reaching an all time high in popularity as an increasing number of individuals have decided to take full responsibility for their own health. As a result of the mainstream popularization of modalities that used to be relegated to the ranks of alternative medicine, many health claims are made by click bait articles and amateur savants. Included in this, sometimes, is a tangled web of ‘facts’ and ‘research’ pertaining to the medicine behind the mechanism of sauna therapy.
At the time of writing, there are 12,000+ peer reviewed journals published by the National Library of Medicine that examine how and why saunas have the potential to have such a positive impact on your health. Unless your primary work is to research the benefits of sauna use on human physiology, then it is doubtful that anyone will have the time to go through the research first-hand and truly understand the mechanisms behind the effectiveness of sauna therapy.
Understanding the similarities, differences, and idiosyncrasies of the most popular forms of sauna therapy requires a cursory understanding of how heat is generated – and exactly what impact heat stress has on the body. While sweat lodges, hot springs, Turkish Hammans, and other cultural and historical forms of heat therapy are all highly effective in healing the body, the most popular forms of saunas today are infrared saunas and traditional saunas.
Why is there a strong division between individuals adamant that the only way to sauna is with a traditional sauna at very high temperatures, while others believe that the high heat is not necessary to benefit from heat therapy modalities?
This article will attempt to examine what happens below the surface of the skin during exposure to heat, or during heat stress, so that you can make a decision for yourself on what the greater truth may be regarding extremely high air temperatures in a sauna versus other forms of heat that may have lower external temperatures.
Why is There So Much Hype About the Necessity for High Heat Saunas?
- Prominent studies using traditional Finnish saunas have been so compelling that many confuse the external mechanism (the specific heat source) for the internal results.
So much of what most folks know about saunas comes from Finland, and this can be demonstrated by the fact that ‘sauna’ is the only Finnish word in the English language. (1) In addition to having deep cultural roots in Finland, saunas also hold a prolific presence in this nordic country. On average there is 1 sauna per household in Finland, and there is even a sauna in the parliament house. This equates to roughly 3 million saunas in Finland. (2) Why is this information important? This information is relevant because for a long time most studies and research were conducted using traditional Finnish saunas, as well as the Finnish population. Many of these publications were wildly sturdy and impactful pieces that demonstrated the importance of heat therapy on human life, and longevity. Many of these studies focused on ‘all-cause mortality’ rates in individuals using saunas over a prolonged period of time. Many individuals, including high profile professionals, took the results to mean that in order to achieve the same results as found in the studies that used traditional Finnish saunas, that a traditional steam sauna was necessary.
The reality is that it is more important to look at the internal bio-chemical reactions in the body to heat stress. In almost every culture throughout the world, humans have created different devices to replicate an artificial fever to induce the healing that occurs during heat stress. For example, sweat lodges have been used, and continue to be used, in a variety of native communities. The lack of research performed on individuals using sweat lodges regularly does not mean that sweat lodges are ineffective, simply that there are not as many studies performed on individuals taking them. (3)
On the other hand, in more recent history, there has been an increasing number of studies performed on individuals using infrared light in their ‘sauna’ structure, or more simply put – infrared saunas.(4) These studies have shown that the source of heat is not as important as the goal of reaching an internal temperature necessary to cause a cascade of biochemical changes induced by heat stress.
Heat stress is a form of hormesis, which simply means a positive stress placed on the body. One example of heat stress is exercise – in the short term it may be uncomfortable, but exercise ultimately yields incredible results on human physiology.
So compelling are the studies performed on subjects using infrared saunas that municipalities across the united states have started to put infrared saunas in fire halls for the purpose of healing firefighters. Infrared saunas are used in clinical studies to treat a myriad of health issues ranging from dentistry, to depression, and even included in oncological care.
What is most important in the sauna is that each individual taking a sauna of any kind can reach an internal temperature of 101.5 degrees fahrenheit, and maintain this for at least 20 minutes. (5) Different heat sources can help individuals reach this goal at varying atmospheric temperatures. When making the decision to use a sauna for therapeutic purposes, remember that it is more important for the internal body temperature to reach a point to create an artificial fever, rather than measuring how hot the air is in the cabin structure.
Biomarkers are much more important in the healing process than the temperature of the air.
Traditional Saunas Versus Infrared Heat: Radiant Heat as Opposed to Convection Heat
The effectiveness of heat transference is much more important than the original source of heat. Traditional saunas rely on convection heat, much like an oven. This means that traditional saunas must heat up the air in the cabin structure to a very high heat before the human body will be able to reach an internal temperature of 101.5 degrees Fahrenheit. This is the fundamental reason why many individuals are such strong proponents of high heat sauna use. Yes, it is important for the air to reach very high temperatures (180-200 degrees Fahrenheit) in a traditional sauna inorder to induce heat stress in the body.
Conversely, infrared saunas use radiant heat (the same basic mechanism as the sun) to induce an artificial fever in the subject using the sauna. This means that the radiant heat of infrared light does not need to heat the air temperature up to as high a degree as a traditional sauna to reach the same goal of elevating the internal temperature of the body.
Take a look at this image to better understand radiant heat versus convection heat.
Infrared light is able to penetrate into the soft tissues of the body and quickly begin the process of hormesis before the individual is even aware that biological changes are taking place.
FIR sauna. (A, B) Comparison of FIR sauna with conventional heated sauna. (C) Cabin incorporating FIR emitting “cold” unit(s) (6)
Internal Temperature Versus Atmospheric Temperature: It is Not About How Hot the Air is, but Rather How Warm The Body Is
“Give me the power to create a fever and I shall cure any disease” – Hippocrates
With so many podcasts and news sources reporting on the benefits of sauna use, there is a lot of misinformation circulating. Don’t get swept up in the confusion, remember that what is most important is what is happening inside the body, rather than in the sauna structure itself.
These means that the effectiveness of a sauna should be measured by its impact on:
- Heat Shock Protein Production
- Internal Body Temperature
- Perspiration
- Cardiovascular Engagement
- Activation of the Autonomic Nervous System
- Improved Circulation
As well as many more physiological reactions that result both directly and indirectly from exposure to heat stress. All of the positive changes that occur as a result of positive heat stress are because of an elevated internal temperature. Whether you choose to use a sweat lodge, a steam room, a traditional Finnish sauna, a far infrared sauna, or a full spectrum infrared sauna, the most important aspect is that the internal temperature is reaching 101.5 degrees Fahrenheit, and that this temperature can be maintained for at least 20 minutes at a time.
There are some benefits afforded through using light as a source of heat rather than an electrical stove. Similarly, there are unique benefits to using a steam room. Ultimately, what heat source you personally choose is less important than the fact that you are actively engaging the hormetic effect on the body through heat stress.
Higher External Heat Does Not Always Mean Better Results For Human Physiology: Light Beyond Heat
While a variety of different heat therapy modalities will have positive effects on human physiology, it is most important that the internal temperature of the participant be considered over the air temperature. Furthermore, in addition to the benefits derived from heat alone, it is worth considering the benefits derived from the light spectrum itself.
NASA, in particular, has published many studies on the benefits of color light as well as infrared light on wound healing, improved function of connective tissues, reduction in pain, as well as improved quality of bone marrow to mention just a few benefits. (4). This signifies that an infrared sauna serves as a dual-purpose therapeutic tool. It provides the advantages of a conventional sauna through its radiant heat waves, while also being capable of raising the body’s core temperature. Moreover, the health benefits stemming from the light itself are substantial, even without the need to increase the temperature significantly.
Ultimately, there is an overwhelming body of research from reputable institutions that demonstrate the benefits of many different types of saunas and heat therapy modalities. It is important to find a heat source that will work for you and your particular preferences and desires.
If you don’t want to get swept up in the hype of ‘high heat is better’, then consider the actual effects on human physiology and the biomarkers needed for improved health and wellness over the air temperature of the cabin structure.
There are a few instances where a traditional sauna may be safer for some individuals. For example, those living with silicone implants will likely do better in convection heat than infrared heat. Although there is not enough evidence to conclusively prove that infrared light will degrade silicone implants, it would be prudent to consider an alternative heat source if you have silicone in your body.
If you are unsure if your joint replacements, pacemaker, or any other specific health concerns require a specific heat source, then be sure to check with your medical provider, or surgeon before engaging in a regular sauna protocol.
Sources Cited:
- https://en.wikipedia.org/wiki/Sauna
- https://www.visitfinland.com/en/articles/5-must-experience-saunas-in-finland/
- https://pubmed.ncbi.nlm.nih.gov/17602408/
- https://spinoff.nasa.gov/NASA-Research-Illuminates-Medical-Uses-of-Light
- https://www.foundmyfitness.com/episodes/ashley-mason
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699878/
