What Is an Infrared Sauna, and How Does It Work?

An infrared sauna is a type of sauna that uses infrared light to heat the body directly, rather than warming the air around you. It’s similar to how sunlight warms your skin on a cool day, but without the harmful ultraviolet (UV) rays.

Unlike visible light, infrared light can’t be seen. However, the heaters inside the sauna often give off a soft red glow as they produce heat.

In a traditional sauna (sometimes called a regular sauna), the air is heated to high temperatures (typically between 150 to 195 degrees Fahrenheit), which then warms your body. Infrared saunas work differently. They use infrared light to heat the body more directly, allowing for lower surrounding air temperature, usually around 120 to 140 degrees Fahrenheit.

Because of this, some people find infrared saunas more comfortable than traditional saunas, while still experiencing a deep, soothing warmth.

An easy way to think about it: A traditional sauna heats the room, and the room heats you. An infrared sauna skips that step and heats your body directly using invisible light waves — similar to how a microwave heats food from the inside out rather than heating the air in the microwave first.

How Does This Impact Your Body?

When your body is exposed to infrared heat, it begins to warm more directly than with hot air alone. This can cause:

• An increase in heart rate, similar to light exercise
• Sweating as your body regulates temperature
• Expanded blood vessels, which improve circulation

“Using a sauna is not a substitute for exercise,” says Anna B. Shannahan, MD, a family medicine and integrative medicine physician at Northwestern Medicine. “Saunas can increase heart rate similar to moderate exercise, but they should complement — not replace — physical activity.”

Some systems use full-spectrum infrared, which combines three different wavelengths of light (far, mid and near) to provide a broader heating effect.

Health Benefits of Infrared Saunas

Research on infrared saunas is still growing, but some studies suggest they may support several areas of health. At this time, most long-term research has been done on traditional saunas.

“The strongest evidence of sauna health benefits comes from traditional saunas,” says Dr. Shannahan. “But infrared saunas still show benefits, including in areas like chronic pain, blood pressure and musculoskeletal conditions.”

Circulation and muscle recovery

Research shows infrared heat increases blood flow, which may:

• Deliver oxygen and nutrients to muscles
• Support recovery after exercise
• Reduce muscle soreness

Stress and relaxation

Many people use saunas to unwind. The gentle heat can:

• Help reduce stress
• Promote relaxation
• Improve mood and overall well-being

Inflammation and joint comfort

Some research suggests infrared sauna use may help reduce pain and stiffness, especially for people with conditions like rheumatoid arthritis.

The heat may help ease:

• Muscle tension
• Joint stiffness
• Ongoing discomfort

Heart and metabolic health

Some research has shown how sauna use may support heart health, including:

• Supporting healthy blood pressure
• Improving circulation
• Promoting relaxation that benefits cardiovascular function

Studies also show sauna sessions may raise heart rate, which may contribute to these effects.

“Infrared sauna research is mostly limited to small, short-term studies. More research is needed,” says Dr. Shannahan. “Many health claims used in marketing for infrared saunas take information from traditional sauna data and may overstate expected benefits.”

Home Sauna vs. Spa Use

Infrared saunas are available both at wellness centers and as a home sauna.

At-home saunas:

• More convenient
• Easy to use regularly
• One-time cost

Spa or gym saunas:

• No equipment purchase required
• Access to larger saunas
• Opportunity to try different types of saunas before buying

The best option depends on your lifestyle and budget.

How Often Should You Use an Infrared Sauna?

Most people use infrared saunas:

• Two to four times per week
• 15 to 30 minutes per session

If you’re new to saunas, start with shorter sessions (about five minutes) and gradually increase the time as your body adjusts. Staying hydrated is important, as sweating can lead to fluid loss.

“Most studies use 15 minutes per session. This is generally long enough to break a sweat, but not so long that you become dehydrated,” says Dr. Shannahan. “To maximize benefits while avoiding dehydration, I recommend shorter sessions more frequently rather than longer sessions less often.”

Potential Risks and Side Effects

Infrared saunas are generally safe for most healthy adults, but side effects can happen, including:

• Dehydration
• Dizziness
• Overheating
  

Some people should use caution, including those who:

• Have a heart condition
• Have high blood pressure
• Are pregnant

“Chronic infrared exposure can cause erythema ab igne (EAI) — also known as toasted skin syndrome — which is a net-like rash,” says Dr. Shannahan. “People with heart conditions and blood pressure issues should discuss using saunas with their doctor.”

A mild EAI rash typically fades on its own within a few months after the heat source is removed.

Talk with your doctor before using a sauna, especially if you have a medical condition or take medications.

Do Infrared Saunas Cause Cancer?

There is no strong evidence that infrared saunas cause cancer.

The type of infrared light used is different from harmful UV light. It does not damage the skin in the same way as UV exposure.

When used properly, infrared saunas are considered safe.

What About Smaller Infrared Devices?

Portable options like infrared blankets and face masks are becoming more popular as well. However, they may not provide the same full-body effects. Research on their effectiveness is limited.

These tools may offer targeted warmth, but they are not a replacement for full sauna sessions.

Common Misconceptions About Infrared Saunas

Myth: Saunas detox the body.
Fact: Sweating removes small amounts of toxins, but the liver and kidneys do most of the body’s detox work.

Myth: More heat means better results.
Fact: Higher temperatures don’t always improve results and can increase the risk of side effects.

Myth: All saunas work the same.
Fact: A traditional sauna and an infrared sauna work differently and may affect the body in different ways.

How To Use Infrared Saunas Safely

To safely add infrared sauna sessions to your routine, Dr. Shannahan recommends the following:

• Start gradually.
• Begin with shorter sessions at lower temperatures and increase duration as tolerated.
• Stay hydrated before, during and after sessions.
• Avoid alcohol when using a sauna, as it can increase the risk of abnormal heart rhythm and dehydration.
• Listen to your body and stop if you feel unwell.

Are Infrared Saunas Right for You?

Whether an infrared sauna is a good fit depends on your individual health, comfort level and personal goals.

Before getting started, it’s important to talk with your doctor, especially if you have an underlying health condition, take medications or are pregnant. Your doctor can help determine whether sauna use is safe based on your individual needs.

Like any wellness habit, infrared sauna use works best when it’s used in moderation and as part of a balanced lifestyle that includes healthy sleep, nutrition and physical activity.