The short answer: current evidence does not show that infrared saunas cause cancer

No major health organization has found that infrared saunas increase cancer risk. The concern usually comes from two places: worry about heat itself, and worry about infrared radiation. Neither has been shown to cause cancer in the way saunas are used.

That said, the research on infrared saunas specifically is still limited. Most studies on heat and cancer risk come from other sources — occupational heat exposure, hot springs, or laboratory work — not from sauna use. What we know is reassuring, but the field has not studied infrared saunas as thoroughly as it has studied other cancer risk factors.

Key Takeaways

  • Infrared radiation from saunas is non-ionizing, meaning it does not have enough energy to damage DNA the way X-rays or UV light do.
  • Heat itself, even intense heat, has not been linked to cancer in humans through sauna or hot spring use.
  • The World Health Organization classifies very hot drinking water as a possible cancer risk, but this refers to thermal injury to the throat, not to external heat exposure.
  • People with certain conditions — heart disease, pregnancy, or uncontrolled high blood pressure — should talk to their doctor before using any sauna, for reasons unrelated to cancer.

How infrared radiation differs from cancer-causing radiation

The word "radiation" can sound alarming, but not all radiation damages cells. Radiation comes in two types: ionizing and non-ionizing. Ionizing radiation — like X-rays, gamma rays, and ultraviolet (UV) light — has enough energy to knock electrons off atoms and break DNA. That damage can lead to cancer. Non-ionizing radiation, which includes infrared light and radio waves, does not have that energy.

Infrared saunas emit infrared radiation, which is non-ionizing. It heats your skin and tissues but does not alter DNA. This is the same type of radiation your body gives off naturally as heat, and the same type that a regular incandescent light bulb produces. The sun emits infrared radiation too — it is what you feel as warmth on a cloudy day.

UV radiation from the sun, by contrast, is ionizing and is a known cancer risk factor. That is why dermatologists warn against tanning beds and unprotected sun exposure. Infrared saunas do not emit UV radiation.

What research shows about heat exposure and cancer

Heat itself — even very high heat — has not been shown to cause cancer in humans. The largest body of evidence comes from studies of people exposed to occupational heat, such as foundry workers or people in hot climates. These studies have not found an increase in cancer rates tied to heat exposure alone.

Hot springs and thermal baths have been used for thousands of years in many cultures. Epidemiologists have studied populations that use them regularly, and heat exposure from these sources has not been linked to cancer risk. The one exception is extremely hot drinking water — the World Health Organization classified drinking very hot liquids as a possible cancer risk, but this refers to thermal injury to the throat tissue itself, not to external heat on the skin.

Sauna use has been studied in Finland, where saunas are common. Research has not found that regular sauna use increases cancer risk. Some studies have even suggested potential health benefits from sauna use, though these findings are preliminary and not yet conclusive.

Why the confusion exists

The concern about infrared saunas often stems from misunderstanding what "radiation" means. In everyday language, people often use "radiation" to mean anything dangerous or invisible. In physics, it simply means energy traveling through space — and most radiation is harmless. Your body emits infrared radiation constantly.

Marketing claims about infrared saunas sometimes overstate their benefits, which can make people skeptical about safety too. If a product is claimed to do many things, people reasonably wonder whether those claims are tested. The honest answer is that infrared saunas have not been studied as extensively as some other health interventions, but the studies that do exist have not raised safety flags about cancer.

Who should be cautious about sauna use for other reasons

While cancer risk is not a concern, certain people should check with their doctor before using any sauna — infrared or traditional. Intense heat can stress the heart and lower blood pressure, which matters if you have heart disease, uncontrolled high blood pressure, or take medications that affect blood pressure.

Pregnant people should avoid saunas, especially in the first trimester, because high body temperature may affect fetal development. People with uncontrolled diabetes, severe dehydration, or certain skin conditions should also talk to their doctor first. These cautions have nothing to do with radiation or cancer — they are about how heat affects the body's systems.

What to know if you use an infrared sauna

If you use an infrared sauna and have no medical reason to avoid it, standard sauna safety applies. Stay hydrated before, during, and after use. Limit sessions to 15 to 20 minutes, especially when starting out. Your body needs time to adjust to the heat. Do not use a sauna if you are ill or feverish.

If you have any health condition — heart disease, high blood pressure, diabetes, or pregnancy — ask your doctor whether sauna use is safe for you. This is true for infrared saunas, traditional saunas, and steam rooms. The question is not about cancer risk but about how heat affects your specific situation.

Frequently Asked Questions

Is infrared radiation the same as the radiation that causes cancer?

No. Infrared radiation is non-ionizing, meaning it does not have enough energy to damage DNA. Cancer-causing radiation — like X-rays and UV light — is ionizing. Infrared is the same type of radiation your body produces naturally as heat.

Are infrared saunas safer than traditional saunas?

Both types use heat, and neither has been shown to increase cancer risk. Infrared saunas may heat the body slightly differently than traditional saunas, but the cancer risk profile is similar. Choose based on comfort and access, not cancer concerns.

Can regular sauna use lower cancer risk?

Some studies suggest potential health benefits from regular sauna use, but the evidence is not yet strong enough to say sauna use prevents cancer. Do not use a sauna as a cancer prevention strategy. Standard prevention measures — not smoking, limiting alcohol, maintaining a healthy weight, and screening when recommended — remain the most evidence-based approaches.

What should I do if I am worried about sauna safety?

Talk to your doctor about your specific situation. If you have heart disease, high blood pressure, pregnancy, or take medications that affect circulation, your doctor needs to know before you use any sauna. For people without these conditions, current evidence does not support cancer concerns.