A sauna (/ˈsaʊnə/; Finnish pronunciation: [ˈsɑunɑ]), or sudatory, is a small room or building designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these facilities. The steam and high heat make the bathers perspire. Infrared therapy is often referred to as a type of sauna, but according to the Finnish sauna organisations, infrared is not a sauna.
History
The oldest-known saunas in Finland were made from pits dug in a slope in the ground and primarily used as dwellings in winter. The sauna featured a fireplace where stones were heated to a high temperature. Water was thrown on the hot stones to produce steam and to give a sensation of increased heat. This would raise the apparent temperature so high that people could take off their clothes. The first Finnish saunas are what nowadays are called savusaunas, or smoke saunas. These differed from present-day saunas in that they were heated by heating a pile of rocks called kiuas by burning large amounts of wood about 6 to 8 hours, and then letting the smoke out before enjoying the löyly, or sauna heat. A properly heated "savusauna" gives heat up to 12 hours.
As a result of the Industrial Revolution, the sauna evolved to use a metal woodstove, or kiuas Finnish pronunciation with a chimney. Air temperatures averaged around 75–100 °C (167–212 °F) but sometimes exceeded 110 °C (230 °F) in a traditional Finnish sauna. When the Finns migrated to other areas of the globe they brought their sauna designs and traditions with them. This led to further evolution of the sauna, including the electric sauna stove, which was introduced in 1938 by Metos Ltd in Vaasa.
Although the culture of sauna nowadays is more or less related to Finnish culture, the evolution of sauna happened around the same time both in Finland and the Baltic countries sharing the same meaning and importance of sauna in daily life, shared still to this day.
The Sauna became very popular especially in Scandinavia and the German speaking regions of Europe after the Second World War. German soldiers had experienced Finnish saunas during their fight against the Soviet Union on the Soviet-Finnish front of WWII, where they fought on the same side.
Saunas were so important to Finnish soldiers that they built saunas not only in mobile tents, but even in bunkers. After the war, the German soldiers brought the habit back to Germany and Austria, where it became popular in the second half of the 20th century. The German sauna culture also became popular in neighbouring countries such as Switzerland, Belgium, the Netherlands and Luxembourg.
Modern Saunas
The sauna known in the western world today originates from Northern Europe. In Finland, there are built-in saunas in almost every house.
Under many circumstances, temperatures approaching and exceeding 100 °C (212 °F) would be completely intolerable and possibly fatal if exposed to long periods of time. Saunas overcome this problem by controlling the humidity. The hottest Finnish saunas have relatively low humidity levels in which steam is generated by pouring water on the hot stones. This allows air temperatures that could boil water to be tolerated and even enjoyed for longer periods of time. Steam baths, such as the Turkish bath, where the humidity approaches 100%, will be set to a much lower temperature of around 40 °C (104 °F) to compensate. The "wet heat" would cause scalding if the temperature were set much higher.
In a typical Finnish sauna, the temperature of the air, the room and the benches is above the dew point even when water is thrown on the hot stones and vaporised. Thus, they remain dry. In contrast, the sauna bathers are at about 38 °C (100 °F), which is below the dew point, so that water is condensed on the bathers' skin. This process releases heat and makes the steam feel hot.
Finer control over the temperature experienced can be achieved by choosing a higher-level bench for those wishing a hotter experience or a lower-level bench for a more moderate temperature. A good sauna has a relatively small temperature gradient between the various seating levels. Doors need to be kept closed and used quickly to maintain the temperature inside.
According to the Guinness Book of World Records, the world's largest sauna is the Koi Sauna in the Thermen & Badewelt Sinsheim, Germany. It measures 166 square meters, holds 150 people and sports a Koi aquarium.
Use
A steam sauna can take 30 minutes to heat up when first started. Some users prefer taking a warm shower beforehand to speed up perspiration in the sauna. When in the sauna users often sit on a towel for hygiene and put a towel over the head if the face feels too hot but the body feels comfortable. In Russia, a felt "banya hat" may be worn to shield the head from the heat; this allows the wearer to increase the heat on the rest of the body. Most adjustment of temperature in a sauna comes from amount of water thrown on the heater; this increases humidity, so that sauna bathers perspire more copiously.
Length of stay in the Sauna | Positioning when in the Sauna
Heating caused by direct radiation will be greatest closest to the stove. Heating from the air will be lower on the lower benches as the hot air rises. Provided the sauna is not crowded, lying on a bench is considered preferable as it gives more even temperature over the body. Heating caused by fresh steam can be very different in different parts of the sauna. As the steam rises directly upwards it will spread across the roof and travel out towards the corners, where it will then be forced downwards.
Consequently, the heat of fresh steam may sometimes be felt most strongly in the furthest corners of the sauna. Users increase duration and the heat gradually over time as they adapt to sauna. When pouring water onto the heater, it will cool down the heater, but carry more heat into the air via advection, making the sauna warmer.
Perspiration is a sign of autonomic responses trying to cool the body. Users are advised to leave the sauna if the heat becomes unbearable or if they feel faint or ill. Some saunas have a thermostat to adjust temperature, but management and other users expect to be consulted before changes are made.
The sauna heater and rocks are very hot—one must stay well clear to avoid injury, particularly when water is poured on the sauna rocks, which creates an immediate blast of steam. Combustibles on or near the heater have been known to result in fire. Contact lenses dry out in the heat. Jewellery or anything metallic, including glasses, will get hot in the sauna and can cause discomfort or burning.
Temperature on different parts of the body can be adjusted by shielding from the steam radiator with a towel. Shielding the face with a towel has been found to reduce the perception of heat. It may be advisable to put an additional towel or special cap on the hair to avoid dryness. Few people can sit directly in front of the heater without feeling too hot from radiant heat, but their overall body temperature may be insufficient. As the person's body is often the coolest object in a sauna room, steam will condense into water on the skin; this can be confused with perspiration.
Cooling down is a part of the sauna cycle and is as important as the heating. Among users it is considered good practice to take a few moments after exiting a sauna before entering a cold plunge, and to enter a plunge pool by stepping into it gradually, rather than immediately immersing fully. In summer, a session is often started with a cold shower. Therapeutic sauna has been shown to aid adaptation, reduce stress hormones, lower blood pressure and improve cardiovascular conditions.
Health effects
Increased frequency of sauna bathing is associated with a reduced risk of sudden cardiac death, cardiovascular disease, and all-cause mortality. Its usage is also associated with lower markers of inflammation in the blood and a reduced risk of high blood pressure. In addition, it is associated with a decreased risk of pneumonia and may temporarily relieve symptoms of the common cold. It is also associated with a reduced risk of dementia and Alzheimer's disease. It has been pointed out that many of the positive health effects reported with sauna usage, in particular its cardiovascular benefits, is associative and may be non-causal.
Saunas may not be safe in cases of unstable angina pectoris, recent heart attack, or severe aortic stenosis. Additionally, there is risk of heat prostration, hyperthermia, heat stroke and even death.
Children and older persons who have heart disease or seizure disorders or those who use alcohol or cocaine are especially vulnerable. Sauna use can affect spermatogenesis, and has been associated with loss of fertility in men lasting up to two months.
Prolonged stay in a sauna may lead to the loss of electrolytes from the body, as after vigorous exercise. The risk of dehydration leading to heat stroke may be reduced by regular sipping of water or isotonic drinks, but not alcohol, during the sauna.
Sauna bathing with heavy drinking of alcoholic beverages or during alcohol withdrawal phase can have serious adverse health effects. With sauna-associated deaths in Finland, individuals usually had an underlying chronic illness. More than 50% were men over the age of 50, and 30% were over 70. Most were also intoxicated.
Technologies
Today there are a wide variety of sauna options. Heat sources include wood, electricity, gas and other more unconventional methods such as solar power. There are wet saunas, dry saunas, smoke saunas, and steam saunas.
There are two main types of stoves: continuous heating and heat storage type. Continuously heating stoves have a small heat capacity and can be heated up on a fast on-demand basis, whereas a heat storage stove has a large heat (stone) capacity and can take much longer to heat.
Around the world
Although cultures in all corners of the world have imported and adapted the sauna, many of the traditional customs have not survived the journey. Today, public perception of saunas, sauna "etiquette" and sauna customs vary hugely from country to country. In many countries sauna going is a recent fashion and attitudes towards saunas are changing, while in others traditions have survived over generations.
Asia
In Iran, most gyms, hotels and almost all public swimming pools have indoor saunas. It is very common for swimming pools to have two saunas which are known in Persian as سونای خشک "dry sauna" and سونای بخار "steam sauna", with the dry type customarily boasting a higher temperature. A cold-water pool (and/or more recently a cold Jacuzzi) is almost always accompanied and towels are usually provided. Adding therapeutic or relaxing essential oils to the rocks is common. In Iran, unlike Finland, sitting in sauna is mostly seen as part of the spa/club culture, rather than a bathing ritual.
It is most usually perceived as a means for relaxation or detoxification (through perspiration). Having a sauna room on a private property is considered a luxury rather than a necessity. Public saunas are segregated and nudity is prohibited.
What is a sauna?
A sauna is typically a room heated to between 70° to 100° Celsius or 158° to 212° Fahrenheit.
Traditional Finnish saunas usually use dry heat, with a relative humidity that is often between 10 and 20 percent. In other sauna types, the moisture is higher. Turkish-style saunas, for example, involve a greater level of humidity. A sauna use can raise the skin temperature to roughly 40° Celsius or 104° Fahrenheit.
As the skin temperature rises, heavy sweating also occurs. The heart rate rises as the body attempts to keep cool. It is not uncommon to lose about a pint of sweat while spending a short time in a sauna.
There are several types of sauna, based on how the room is heated.
These include:
Wood burning: Wood is used to heat the sauna room and sauna rocks. Wood-burning saunas are usually low in humidity and high in temperature.
Electrically heated: Similar to wood-burning saunas, electrically-heated saunas have high temperatures and low humidity. An electrical heater, attached to the floor, heats the sauna room.
Infrared room: Far-infrared saunas (FIRS) are different to wood-burning and electrically-heated saunas. Special lamps use light waves to heat a person’s body, not the entire room. Temperatures are typically lower than other saunas, but the person sweats in a similar way. Usually, infrared saunas are about 60° Celsius.
Steam room: These are different from saunas. Instead of dry heat, a steam room involves high humidity and moist heat.
What does u wear in a sauna?
A classic, oversized T-shirt, loose-fitting cotton wrap, and shorts are always an excellent choice for the sauna. They will absorb excess heat and let your skin breathe freely. Always wear clean clothes, dressed on just before getting inside.
Can you lose belly fat in a sauna?
To those wanting to have a good sweat, saunas can be the best place. ... But for fitness experts, sauna can do little to help you in weight loss. Sweating while sitting in a room for a few minutes only cuts water weight, according to Health line. That means you only lose water from your body and not burn fats.
What are the Health benefits of a sauna?
The main benefits proposed for saunas are for relaxation and cardiovascular health. However, a sauna may not be suitable for everyone. Regardless of how a sauna is heated, or the humidity level, the effects on the body are similar.
When a person sits in a sauna, their heart rate increases and blood vessels widen. This increases circulation, in a similar way too low to moderate exercise depending on the duration of sauna use. Heart rate may increase to 100-150 beats a minute while using a sauna. This may bring some health benefits.
Easing pain
Increased circulation may help reduce muscle soreness, improve joint movement, and ease arthritis pain.
Reducing stress levels
As the heat in a sauna improves circulation, it may also promote relaxation. This can improve feelings of well-being.
Improving cardiovascular health
It may provide benefits for cardiovascular health that resemble those derived from exercise. Participants who used the sauna two to three times a week were 22% less likely to experience sudden cardiac death than those who only used it once a week. Those who used a sauna four to seven times a week were 63% less likely to experience sudden cardiac death and 50% less likely to die from cardiovascular disease than those who only used a sauna once a week.
Anyone who has a cardiovascular problem or who is pregnant should seek medical advice before using a sauna.
What are the Health risks of a sauna?
Skin problems
A dry sauna dries the skin during use. Some people with psoriasis may find that their symptoms reduce while using a sauna, but those with atopic dermatitis may find that it worsens.
Asthma
People with asthma may find relief from some symptoms as a result of using a sauna. A sauna may help open airways, loosen phlegm, and reduce stress.
Blood pressure risks
Switching between the heat of a sauna and cold water in a swimming pool is not advisable, as it can raise blood pressure. A sauna use may also cause blood pressure to fall, so people with low blood pressure should talk to their doctor to make sure sauna use is safe. People who have recently had a heart attack should also talk to their doctor first.
Dehydration risk
Dehydration can result from fluid loss while sweating. People with certain conditions, such as kidney disease, may be at a higher risk of dehydration. The increased temperatures can also lead to dizziness and nausea in some people.
Precautions
To avoid any negative health effects, the following precautions are also advised:
Avoid alcohol
Alcohol increases the risk of dehydration, hypotension, arrhythmia, and sudden death. A year-long study of people in Finland who experienced sudden death showed that in 1.8% of cases, the person had had a sauna within the last 3 hours, and in 1.7% of cases, they had done so in the last 24 hours. Many of these had consumed alcohol.
Limit time spent in a sauna
Do not spend more than 20 minutes at a time in a sauna. First-time users should spend a maximum of 5 to 10 minutes. As they get used to the heat, they can slowly increase the time to about 20 minutes.
Drink plenty of water
Whatever type of sauna a person uses, it is important to replace the fluids lost from sweating. People should drink about two to four glasses of water after using a sauna.
Avoid sauna use if ill
People who are ill should also wait until they recover before using a sauna. Women who are pregnant or those with certain medical conditions, such as low blood pressure, should ask their doctor before sauna use.
Supervise children
Children aged 6 and above are safe to use a sauna, but should be supervised when doing so. They should spend no longer than 15 minutes in there at one time.
Health myths
False: Sweating removes toxins
One is that sweating can remove toxins from the body. It’s true that sweating occurs during sauna use, but there is no scientific research that proves sweating detoxifies the body. Toxins such as alcohol, mercury, and aluminium are mainly removed by the kidneys, liver, and intestines.