Infrared vs traditional saunas: what they are and what the evidence says

Different saunas and their purposes

While the different types of sauna often live side-by-side in modern spa sanctuaries, each brings a different experience and different benefits, which is why lots of spas recommend moving from one to the other as part of a thermal suite.

When we talk about traditional saunas, we’re usually referring to Finnish saunas where wood is burned to generate heat and the air is usually around 80°C to 100°C. As the body heats up, it causes the heart to beat faster, blood vessels to dilate and blood pressure temporarily drops.

A 2024 study wrote: "Finnish saunas have the most consistent and robust evidence regarding health benefits and they have been shown to decrease the risk of health outcomes such as hypertension, cardiovascular disease, thromboembolism, dementia, and respiratory conditions".

By contrast, infrared saunas use light to create heat at milder air temperatures (usually 45°C to 60°C), offering a deep, gentle tissue warming without extreme ambient heat. As a result, they tend to focus the benefits on detox and heating soft tissue. The Cleveland Clinic lists benefits as including:

• Improved heart health
• Soothing sore muscles
• Pain relief
• Relaxation
• Improved sleep

How it works

1. Traditional Finnish saunas

In a traditional sauna, a stove typically heats rocks, which in turn heat the air. When water is thrown onto the stones, steam is released, momentarily raising humidity and making the heat feel even more intense. Your body absorbs this heat through the skin, causing an increase in heart rate and heavy sweating to cool yourself down.

2. Infrared saunas

Infrared saunas use heating elements that emit light within the infrared spectrum, and as tissue absorbs far-infrared waves (FIR), the energy penetrates the tissue. As a result, you experience deep, relaxing warmth at more comfortable temperatures.

What evidence supports sauna benefits

Traditional saunas

Traditional saunas boast the most extensive, long-term scientific backing of any thermal therapy, and are also widely recognised on an anecdotal basis, with people swearing by the concept for centuries..

• Cardiovascular benefits: A seminal 20-year cohort study published in JAMA Internal Medicine by Dr. Jari Laukkanen and colleagues followed over 2,300 participants. The research demonstrated that those who used a Finnish sauna four to seven times per week had a 50% lower risk of fatal cardiovascular disease and a 40% lower all-cause mortality rate compared to once-weekly users.
• Systemic health: Comprehensive reviews in Mayo Clinic Proceedings show regular Finnish sauna use lowers blood pressure, reduces arterial stiffness, decreases systemic inflammation, and may have protective effects on neurocognitive conditions like dementia.

Infrared saunas

The research on infrared saunas, particularly far-infrared (FIR) exposure, is solid but primarily conducted in clinical rather than large settings.

• Heart and blood flow: A clinical review on PubMed/PMC confirms FIR therapy improves vascular function, reduces blood pressure, and boosts cardiac output.
• Pain and fatigue: Small clinical trials show FIR sauna exposure offers short-term relief for chronic pain, fibromyalgia, and stiffness, making it ideal for those who cannot tolerate traditional high temperatures.

Which sauna is right for you?

• Choose traditional saunas if: You like intense heat, enjoy social bathing culture, and want maximum cardiovascular heat-conditioning.
• Choose infrared saunas if: You struggle with heavy heat, suffer from chronic joint pain or fatigue, or want a gentle sweat and cardiovascular boost at manageable temperatures.