Sauna is but one form of Thermal Experience. Banya’s, Sweat Lodges, IR Cabins, Laconiums, Steam Baths and others fill out the world of Sweat Bathing. There are also the worlds of hot water, cold water, and cold air (Cryotherapy). And for extra fun the multi-experience facilities like Hammans.
Table of Contents:
- Overview of Thermal Bathing
- A Variety of Thermal Experiences
- Glossary
- Books / References
Common Accurate Terminology – It’s really difficult to communicate when we have different ideas and definitions of what things are. Accurate terminology is critical for good communication. So this is both an introduction and discussion of some of the wonderful variety of thermal experiences in the world as well as a lexicon and taxonomy of things thermal.
One problem today, particularly in the medical/health/wellness worlds, is a lack of definition for various thermal experiences. Imagine if a doctor prescribed ‘acetaminophen’ for a headache but the pharmacist’s definition was a corticosteroid. That’s what we have today with thermal experiences. Someone will say that a ‘sauna’ helped with their eczema but this, at least in the U.S. and UK could be a Finnish Sauna, Bio Sauna, IR booth, Banya, Sweat Cabin, Steam Bath, Caldarium or something totally different.
We need to begin using correct and common terminology, particularly in medical/health contexts. As well, in medical/health contexts we need to specify some critical parameters with regard to temperatures, humidity, steam and practice. And practice specified in terms of Sessions, Rounds, the Structure of each Round (time in hot room, type of hot room, time in cold, type of cold, shower/rinse elements, etc.). We need to consider and specify the quality of the sauna. A hot box with low benches resulting in considerable stratification, poor ventilation resulting in high CO2, and a lot of radiant from the heater will likely result in very different outcomes than a proper sauna with higher benches resulting in more even convective temps, good ventilation providing for fresh air and low CO2, and little or no radiant.
Social – Like sauna, all of these thermal experiences except IR Cabins are social activities and this was and is today a very key element. Besides enjoyment, the social aspect plays a critical role in improved health.
While Finnish sauna is my personal favorite, I also enjoy steam baths, laconiums, caldariums and others. You might have different preferences. (click on the image for a larger view).
Note: Primary Heating Mechanism are all about ±20% but give a good idea of the relative contribution of each source.
Heat: Convective, Radiant and Conductive – What distinguishes sauna from other forms of sweat bathing and what’s made it so popular in Europe is an experience of gentle even convective heat with no noticeable radiant and very little stratification.
Sauna is the only thermal experience where bathers are heated almost exclusively by gentle convective heat. A Banya has a bit of noticeable radiant from the oven. Sweat Cabin’s (Kuuma, Nippa, etc.) have more radiant still and less convection while IR Booths, Laconiums and Tepidariums are primarily radiant (but in the latter two very mass source so very even on all sides). Finally we have steam baths where we’re back to no noticeable radiant while conductive via steam becomes an important element.
There’s a reason that there are so many saunas in the world and that on our chart they’re clustered down in the lower left corner of convection heat and very low stratification – most people find these to be the most comfortable and enjoyable of all thermal experiences.
A steam bath is actually quite similar to a sauna. There’s a progression of Finnish Sauna > Bio Sauna > Steam Bath (6 o’clock > 7 > 8 o’clock below) of decreasing temp, increasing humidity so increasing conductive heat and with no noticeable radiant. So the Sweat Bathing taxonomy chart above kind of wraps back around from steam bath to bio sauna.
Similarly, the key difference between a bio-sauna and banya is that in a banya we feel radiant heat from the oven on our side facing the oven. Otherwise these are the same from a general temp and humidity standpoint.
While I prefer a true sauna, as it is known to Finns in Finland, I still enjoy some of these other similar experiences occasionally. Sticky Toffee Pudding, Banofee Pie and Peach Cobbler are three very different foods but I still love all three. I would never try to sell someone Sticky Toffee Pudding and call it Peach Cobbler though. Note: It has taken some bit of work to figure out what’s what with these, particularly Banya. I think I’m getting there but would appreciate any thoughts on making this more accurate.
Elements Of A Thermal Experience
There are five elements to consider with different thermal experiences; Physical, Setup, Practice, Culture, and Spiritual. Here we are focusing primarily on the first three that are the common foundation regardless of cultural or spiritual elements.
Physical – This is the physical space including thermal rooms and other related spaces. This is fixed and usually remains the same from day to day and decade to decade. This is the foundation for a good experience and getting it right is critical.
Setup – How do we setup the physical space for our use. This is primarily what temp and humidity do we want and how will we control these. It is not uncommon for hotels in Europe to setup their sauna as a Finnish sauna one day and a Bio sauna the next. A home sauna may similarly have the capability to be a Finnish sauna one day, bio another and even setup as a hot yoga studio with 35°c temps and fold-up benches. Similarly a Banya can be a traditional banya one day and a hot banya another day. A steam room w/ heated walls and floor can be setup as a traditional steam shower in the morning and a laconium in the evening.
Practice – How do we use the spaces. Even the best sauna or steam bath will offer a blah experience if we just sit in it for 15 minutes and then take a hot shower. Our routine; showering, cooling off, hydrating is important as are other bits. A sauna setup as a Finnish Sauna can be used individually for multiple hot/cold rounds or have rounds led by an aufgus master. Do we use a vihta? A key part of the practice of banya is Parenie thermal massage.
Cultural – Various thermal experiences are key parts of some cultures or carry cultural significance. Sauna is certainly an important element of Finland’s culture and has been for centuries. And similarly Banya’s in Russia or Onsen’s in Japan.
Spiritual – In many cultures there’s a spiritual element attached to thermal experiences. The North American Sweat Lodge is an important spiritual ceremony. In Finnish sauna history there are elements of both Shamanism and Christianity.
A Variety Of Thermal Experiences
Russian Banya – Banya’s generally sit kind of in the middle between Saunas and IR Cabins in terms of radiant vs convective heat. They look somewhat like saunas but there are some critical differences. There are four different types of Banya; Traditional, Modern, Hot and Bio.
The hot room or ‘Parilka’ in Russian Banya’s do not have the löyly that is critical to Finnish sauna. Parilka’s are more constant humidity vs the contrast of dry with bursts of steam in a Finnish Sauna and Parilka’s don’t have the more even convective heat löyly pocket of saunas. While the key goal in a sauna is for there to be no noticeable radiant heat, there is intentional and considerable radiant in a Banya where the very large floor to ceiling oven produces a large though also somewhat even, milder and more comfortable radiant than a smaller oven or stove.
Due to the radiant heat, Banyas may have only two bench levels compared to the three bench levels that are critical for löyly in a sauna so banyas often have more convective stratification but since convection is not as prominent this may not be as noticeable to regular banya users.
Traditional Russian Banya ‘ovens’ (above) are typically much larger and more enclosed than a sauna heater and also function somewhat similarly to a steam generator than the open convective dryer heat of a sauna heater that you throw water on for temporary humidity. The very large stone slab or tile surface that’s producing radiant heat is able to produce a ‘softer’ radiant that is more even on bathers since it is less point-source than a smaller stove and because of the size of the radiant surface the radiant heat dissipates much slower so a moderate amount of radiant produced by the oven can be felt more evenly by bathers. Want to build your own?
There is also a smaller electric Modern Banya oven that can look somewhat similar to a sauna heater but differs in several ways including usually having heavy stone slabs for the carcass to create somewhat even radiant heat and an interior water reservoir that constantly drips water on to the stones (and typically on only the lower stones). These may also have a pot of water hanging over the stones that constantly drips water on the upper stones to help maintain the humidity. Many Russians say that these are very inferior to the larger traditional ovens because the radiant heat and steam are more harsh and not as even. Builders will often do floor to ceiling stone slabs on the walls behind these to help provide somewhat more even radiant to sort of emulate a larger traditional Banya oven.
Banya is traditionally lower temp (65°c ± 15°c / 131°f ± 27°f ) + higher and more constant humidity (30-70% RH) than a Sauna. There is also a Hot Banya experience that is quite high temps, about 140°c, and very low to nearly no humidity. Some Russians will treat their Parilka somewhat like a Sauna with lower humidity and temps around 80-105°c though a major difference is that the oven in these is producing more radiant heat than would a sauna heater. There is also what I think can best be described as a Bio-Banya that, similar to a bio-sauna is slightly lower temp than traditional and somewhat higher humidity of perhaps 50%.
Banya includes Parenie thermal massage as an essential element, typically by a masseuse using a venik of birch, oak or eucalyptus. Using a venik is optional and less formal with sauna and often done by the bather themselves or whoever is sitting next to them. While saunas in Finland nearly always include a changing room, I’m told that having three rooms (steam or ‘parilka’, washing or ‘moyka’ and the critical ‘predbannik’ for relaxing) is essential to Banya.
Interestingly Russians will often say that Banya is just like Finnish Sauna while Finns say, rightly, that it is very different. This is likely because someone who is accustomed to no noticeable radiant in a sauna will notice the radiant from the banya oven while someone accustomed to the radiant + convection may not be as likely to notice the absence of radiant, especially if convective temps are very even.
For more on Banyas: Bryon MacWilliams book ‘With Light Steam’ and Ethan Pollock’s ‘Without The Banya We Would Perish’ are both excellent. And how a banya oven is built (Note the lack of stones or any convective air flow in this oven so this one will produce a very radiant experience. Some banya ovens do have stones (rather than steel ingots) and some airflow up through them for kind of a balanced radiant-convective experience.)
Sweat Lodge or Temazcal– These are common among many Indigenous Americans and seem somewhat similar to a Finnish Smoke Sauna except that typically the stones are heated outside and then carried in to the tent. Sweat lodges are more radiant heat vs the convective heat of a sauna. Sweat Lodges are also a spiritual ritual for many Indigenous Americans.
Sweat Cabin – These are heated by heavy steel stoves such as Kuuma, Nippa and others. Many in North America call these a sauna, though they are actually quite different. These are kind of a hybrid of a Sweat Lodge, Banya and IR Cabin. They have radiant heat from a heavy steel stove rather than the convective heat and convective loop of a sauna. These generally do not have the löyly cavity that a sauna has. They will often have lower ceilings and benches since with the radiant heat there is less benefit to higher as there is for a Sauna with convective heat. In practice bathers will typically use them like a Finnish Sauna by throwing water on the stones to increase humidity. In this they are perhaps similar to a Modern Banya though with harsher and less even radiant heat and less convective heat.
Infrared Cabin – This is not a sauna despite the misappropriation of the name in the U.S. and is a very different experience than sauna despite what marketing people say. Most people who have experienced both usually have a preference, often strong, for sauna.
There are two flavors of IR; Far Infrared or FIR and Near Infrared or NIR. Each is a bit different from a comfort/enjoyment standpoint. Both FIR and NIR include potential health benefits though the lists of benefits differ for NIR, FIR and Sauna. One studied benefit is using FIR for Waon Therapy to improve respiratory function for people with COPD. Other health benefits are being studied so as time goes on we’ll know more. There are some health concerns with IR such as EMF exposure though similar to the benefits these have not yet been studied enough to know if they are real or imagined.
Laconium – A Laconium (≈ 60°c, naturally dry) looks similar to a Steam Bath with its stone or tile walls. It functions more like an IR Cabin though as the floor and walls (and sometimes ceiling) are heated and radiate this heat to bathers. A Laconium provides a more even and pleasant heat than an IR Cabin and typically has very low humidity though bathers can throw water on the walls to raise the humidity as they desire.
Thanks to the more even very mass source radiant heat and larger space, laconiums are more social than an IR booth.
Tepidarium – A Tepidarium (≈ 37°c (body temp), semi dry) is similar to a Laconium in that bathers are heated by radiant from the stone or tile walls and floor but the ambient temperature is lower and humidity may be slightly higher. Loungers are heated as well and are noticeably warmer, typically 37°c. Today they are often used as a room to lay in after a massage. Bathers typically lay naked though sometimes swaddled in a blanket.
Caldarium – A Caldarium (≈ 40-50°c, near 100% humidity) is similar to a steam bath with the primary difference being that a caldarium includes radiant heat from the walls and floor.
Danarium – A low humidity Steam Bath (≈60°c, 60% relative humidity) or Caldarium without the radiant. It’s built like a steam bath but for use is setup with temps and humidity that are actually quite similar to a Bio-Sauna.
Steam Bath / Steam Shower – Lower temperature (40°c ± 10°c / 105°f ± 20°f ) and very high humidity of 90-100%. If you think about a humidity continuum from Finnish Sauna to the moderate humidity of a Bio Sauna, a Steam Bath is simply the next step. It’s also a Caldarium without the radiant. Rather than the wood walls of a Sauna the walls of a Steam Bath are typically tile or stone.
Steam Baths do appear to have a number of health benefits, some overlapping with Sauna. There may be a higher risk of bacterial transmission in a Steam Bath so hygiene of bathers and the facility is critical.
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Some multi-experience facilities:
Thermarium — A stone/tiled space that includes heated walls, floor and possibly ceiling along with a steam generator to provide the experiences of a laconium, caldarium, danarium and often a tepidarium and steam bath. These capabilities can be included in a steam shower or steam room. Heating is typically via hydronic but can be electric as well.
Ideally for a shared space this room should be about 10’ x 8’ x 8’ for a single tepidarium lounger and 10x10x8 for two loungers. As small as 5x5x8 can possible work though. Ideally the tepidarium lounger is not directly next to a wall so that bathers feel even gentle radiant from all around rather than more intense from the left or right.
There is a great opportunity for a company like Kohler or Masco to offer a single integrated system for this (including controlled ventilation to maintain healthy CO2 levels).
Thermal Suite — A Thermal Suite is a dedicated area with a collection of thermal experiences found in a home, flat, office, hotel or dedicated facility. This suite of thermal experiences can be inside, outside or both.
An good thermal suite for a private home might be a central area with a 4-person plunge pool (16°c / 150x300x120d (5’x10’x4’)) and four showers, a 4-person sauna and a 4-person thermarium. The central area should have easy access to outside and ideally some large openable windows/doors to see out, let sun, moon and star light in and provide for fresh air. A conservatory or orangery can work well for the central area.
Roman Bath – Roman Baths are perhaps the best known of ancient thermal bathing and from where we get Laconium, Tepidarium, Caldarium, Frigidarium and other bits. Roman baths are however likely descendants of Greek bathing activities (and laconium likely from the Greek laconia) which are themselves likely based on more ancient activities.
Roman Baths often had a more formal proscribed ritual done in a larger multi-room facility. It is believed that a typical ritual was Tepidarium (warm) > Caldarium (hot) > Frigidarium (cold) though some appear to have been built for a specific Caldarium > Tepidarium > Frigidarium. Alternate rituals might have included a second stop in the Frigidarium. Many also included a Laconium (hotter (60°c ?) and dryer than a Tepidarium).
Victorian Turkish Bath / Roman-Irish Bath – Victoria Turkish Baths and Roman-Irish Baths are descendents of Roman baths and believed originated by Dr. Richard Barter in the mid 19th century. Despite the name, Victorian Turkish Baths are actually somewhat different from Turkish Baths. Generally the best Roman-Irish today is considered to be Friedrichsbad Spa (plan above) in Baden-Baden Germany with their 17-step process. Some interesting info at VictorianTurkishBath.org
Hamman / Turkish Bath – These are descendants of Roman Baths from when Rome controlled the Maghreb (Northern Africa) and what is today Turkey. The Roman baths had become very popular among the Muslim populations of these areas and over time were adapted as a cleansing ritual in Islam.
Ozone Cabin – Similar to IR Cabins these are not saunas in any way except the misappropriation of the name and are also usually not a thermal experience.
Hot Springs, Onsen, Hot Tubs, Salt Baths and Mud Baths are other more liquid forms for thermal experiences. For the ultimate hot springs and mud baths experience spend a week in Bormio Italy. You can hike to mountain huts for lunch during the day and then enjoy a hot spring, mud bath or sauna in the evening before having a wonderful dinner. The Onsens of Japan (there are three varieties; rotenburo, utaseyu, and konyoku) are something everyone should experience once in their life.
Snow Rooms, Cryotherapy and similar cold air experiences are also popular options in this realm.
At spa’s throughout Europe you’ll find numerous other experiences like salt water floating pools, Kneipp walks and brine cabins.
Getting a bit outside of thermal experiences; Halotherapy is an experience of breathing salt air which can help with a number of ailments. A human-made room for this is sometimes called a Broncharium which will typically have a temp of about 20°c (68°f) and either have walls of salt (typically Himalayan) or a salt air generator. Speleotherapy or Spelarium is the real cave version where you actually enter a salt mine. A Spectaculum is sound and light therapy.
Glossary
In addition to the above.
Note: Also see the glossary in the back of the Global Wellness Institute’s Hydrothermal Guide.
After Löyly – Sitting on the upper bench of a sauna after it’s cooled a bit to enjoy the warmth of the radiant heat from the wall on bathers back.
Aufgus – A ritual performed by an Aufgus Master that may include a variety of infusions, towel waving to distribute heat, steam and infusions, dance and other elements.
Continental Bathing Tradition – Everyone in saunas, steam baths and similar are required to be nude and sexes are mixed. Sand clocks for timing how long to stay in are common.
Day / Session – We typically do multiple Rounds per day or session.
Dry Sauna – There’s really no such thing. Steam is a critical element of sauna. Without steam, bursts in a Finnish sauna or constant humidity in a bio sauna, it is not a sauna.
Finnish Bathing Tradition – Everyone in saunas, steam baths and similar are usually nude though not always. Family and close friends are mixed sex, otherwise sexes are separated, typically with women first and then everyone is welcome to join. Sand clocks are rare and people are told to stay in as long as they feel comfortable.
Foot Bench – The second highest bench and the one that we put our feet on when sitting on the sitting bench. The foot bench is typically about 40cm (16”) below the sitting bench.
Gradier Sauna – Somewhat similar to a hay sauna. Temp about 50°c. In the room is a graduation tower of blackthorn with a brine (salt water) dripping over the blackthorn to create a natural infusion.
Graduation Tower – A wooden tower filled with brushwood (typically Blackthorn) that results in concentrated salt air. Wiki: Graduation Tower.
Hay Sauna – A sauna that includes some walls lined with natural local hay. These are seen primarily in alpine areas.
Löyly – The purity, freshness, temperature, humidity and evenness of the air in the sauna.
Round – A contrast sequence of Shower > Hot > Cold > Relax > Hydrate > Repeat. Rounds are typically repeated numerous times during a sauna session. An average perhaps is 3 rounds per session but more or fewer is common.
Sitting Bench – The highest bench. Typically about 120-130cm (48-51”) below the ceiling.
Sauna Master / Aufgus Master – Someone trained extensively in the use and benefits of sauna. Their primary role is to guide bathers in proper use and etiquette. An add-on role is that of entertainer.
Thermal Suite - A space with multiple thermal experiences. Typically at least a sauna, steam bath, cold plunge and rest/relaxation areas. These areas are typically textile-free (nude) and so usually at least partially partitioned from textile areas.
Books / References
Thermal Bathing:
Victorian Turkish Baths (Malcom Shifrin) – This is focused on a different place and period but I think also provides a good historic overview in an interesting context.
Cathedrals of the Flesh (Alexia Brue) – A wonderful and entertaining overview of current bathing traditions around the world.
Thermé et Balnea (Inge Nielsen) – This seems to me the best single resources for those interested in a deep dive in to ancient Roman bathing.
VictorianTurkishBath.org – Malcom Shifrin’s website.
Sweat Bathing:
Sweat (Mikkel Aaland) – Also watch Mikkel’s streaming series ‘Perfect Sweat’.
Banya:
With Light Steam (Bryon MacWilliams) – A wonderful description and stories of Russian banya from while Bryon lived and worked in Moscow as a Journalist.
Without the Banya We Would Perish (Ethan Pollock)