Healing Heat: Sauna types and health benefits

Having regular (3-4 times p/w) saunas is one of the easiest and most affordable ways to boost your overall physical and mental health. Many researchers agree that if done properly sauna users showcase improvements in cardiovascular health, lower blood pressure, reduced risk of respiratory diseases, muscle recovery/pain relief, skin health, improved sleep, mental health and stress reduction. The results are quite staggering considering how easy, accessible, and enjoyable the whole process is, which explains why their use dates back as far as 2,000 years.

A brief history of ‘Sauna’

The first saunas were built in Finland as pits dug into slopes in the ground, which were then heated with stones. These early saunas, known as “savusaunas” or “smoke saunas,” had no chimneys, and the smoke from the fire would fill the room before being vented out. Once the smoke cleared, the residual heat kept the sauna warm, allowing people to enjoy its relaxing and health benefits. Saunas became central to Finnish culture, serving not only as places for bathing and relaxation but also for various social and spiritual activities. In some cultures, saunas were even used for childbirth, indicating their significance in daily life. 

As the sauna tradition evolved, the Finns developed different types, including wood-burning, electric, and modern infrared saunas. Many other countries and cultures also appreciated the benefits of heat bathing for its physical, mental, and social benefits such as the Russian Banya, Native American sweat lodges, Turkish Hamman, Japanese Onsen, Korean Jjimjilbang, and Roman Thermae to name a few. 

Thermoregulation: The body’s thermostat

We certainly trust our dear Finnish friends with their intuition and depth of research, but what is actually happening in the body when we are exposed to extreme temperatures like heat. See, humans consistently maintain a core body temperature of around “37 +/- 0.5°C (98.6 +/- 0.9°F)” for healthy metabolic functioning¹. This process is called thermoregulation, where your core body temperature is balanced through the generation and loss of heat. The brain’s hypothalamus, specifically the hypothalamic thermoregulatory center located in the preoptic area, functions like the human body’s thermostat regulating and setting temperature homeostasis¹.

Inside the hypothalamus there are temperature sensors called peripheral and central thermoreceptors; these are nerve cells that receive information from important parts of the body. The peripheral thermoreceptors sense surface temperatures and carry this information from the skin. The central thermoreceptors sense core temperature and signal from the spinal cord, viscera, and hypothalamus. When the body temperature changes these thermoreceptors activate and inform the mechanism in the preoptic part of the hypothalamus to regulate the temperature by increasing or decreasing heat returning it back to baseline¹.

Dry vs. Wet Sauna 

Let’s clarify a few key definitions to distinguish between the different types of saunas…

A dry sauna involves no steam and no water, it heats the air to a high temperature (usually ranging from 160-200°F) using electric stoves or wood fires and allows humidity levels to stay low. While a wet sauna is a traditional (Finnish) sauna or steamy bath that uses a heater and sauna rocks to produce steam, it pumps steam into the air and maintains a high humidity level of 20% up to 100% depending on preference.

Choosing which heat is best for you is paramount, hence the following serves to provide the basic information to help you choose your ideal healing experience. Whilst many different types of saunas exist today, they can be distilled down to three main sources of heat which function like the saunas’ heart pumping heat through an enclosed area. 

1. Wood-Fired 

The Wood-fired sauna is essentially a wood-burning stove that heats sauna rocks, creating a more traditional and relaxing atmosphere for your sauna experience. Unlike electric saunas, they take longer to heat up and require a chimney for ventilation and you’d ideally burn a hardwood species like maple, oak or birch as opposed to a softwood as they work better for maintaining that heat for longer periods. The health benefits of wood-fired saunas include stress reduction, improved cardiovascular health, respiratory relief, and pain alleviation due to increased circulation and relaxation. 

Pro Tip: Incorporate specific diluted essential oils into your steamy sauna session for added health benefits.

2. Electric 

Electric saunas have become extremely popular in recent years as a result of their quick and convenient ease of use. These saunas are powered by electric heaters, which are typically built into the sauna room. The ability to adjust and control the temperature, duration, and humidity is literally at your fingertips using either the control panel on the heater, or a remote. In addition, some modern electric sauna heaters are programmable and often have inbuilt functions for added ease of use and safety.

Pro tip: Prepare your mind and body before you start. That means drink plenty of water in the hours leading up to your sauna session, don’t eat a meal before your session (ideally a light snack), and have a shower before to prep skin pores.

3. Infrared

Infrared saunas are popular in the wellness community for their health benefits and overall positive effects. They use infrared wavelengths, which are invisible rays from the sun that provide warmth without harmful ultraviolet rays. 

Three types of infrared wavelengths:

1. Near Infrared: Penetrates deeply into the body, enhancing core thermal energy and stimulating cellular energy production through ATP.
2. Mid Infrared: Captured by water molecules in the body, it temporarily boosts circulation, blood flow, heart rate, and metabolism.
3. Far Infrared: Closest to the body’s natural heat emission, it is absorbed by water molecules and enhances the body’s energy in a natural way.

The infrared sauna heaters use the infrared spectrum to promote relaxation and other wellness benefits. In an infrared sauna, the air temperature is less important than the quality of the infrared heat so you can warm up your infrared sauna for about 15 minutes and get in, and you will warm up with the sauna. As your body absorbs the infrared heat, this will increase thermal energy inducing a deep and relaxing sweat. Using your infrared sauna at lower temperatures means you can stay in longer and get more benefit.

Pro Tip: Try 10-15 min sauna rounds, for example, round 1=15 mins dry sauna, followed by 5-15 mins cool down outside, in a cold shower, or a few mins in an ice bath. Then, round 2 = 15 mins wet sauna with fresh steam. Lastly followed by cool down. Add another round if need.

References:

¹ Osilla, E. V., Marsidi, J. L., Shumway, K. R., & Sharma, S. (2023). Physiology, Temperature Regulation. In StatPearls. StatPearls Publishing.

_{Written by: Dominic Fransen}