Infrared Sauna Side Effects

Infrared sauna side effects are mild, uncommon, and almost always preventable. The most frequently reported ones include temporary lightheadedness, dehydration, and slight skin redness. A 2018 systematic review published in Evidence-Based Complementary and Alternative Medicine analyzed 40 clinical studies involving 3,855 participants and found that the vast majority reported beneficial health effects. Only one small study of 10 participants reported an adverse outcome, a temporary disruption in sperm production that reversed completely once sauna use stopped. This article covers the side effects you should know about, how to prevent each one, and what the research says about using infrared saunas safely.

What Are the Most Common Infrared Sauna Side Effects?

The most common infrared sauna side effects are mild and short-lived. According to the 2018 systematic review by Hussain and Cohen at RMIT University, the potential side effects reported across the studies included heat discomfort or intolerance (rated as mild to moderate), low blood pressure, lightheadedness, and airway irritation. Medical case reports have also noted rare instances of burns from direct contact with heating elements, fainting in people who stayed in too long, and falls related to dizziness.

These side effects are not unique to infrared saunas. They happen with any form of heat therapy when basic precautions are not followed. The good news is that every one of them is avoidable with proper hydration, reasonable session lengths, and awareness of your body's signals. We see hundreds of infrared sauna sessions and the vast majority of people walk out feeling relaxed, recharged, and better than when they walked in.

How to Prevent Dehydration During an Infrared Sauna Session

Preventing dehydration during an infrared sauna session starts with drinking water before you ever sit down. A typical 30 to 45 minute session produces 1 to 2 pounds of sweat. That is a significant amount of fluid loss in a short time. Without replacing it, you can end up with headaches, fatigue, or dizziness.

Drink 16 to 20 ounces of water two to three hours before your session. This gives your body time to absorb and distribute the fluid. Keep water with you inside the sauna and take small sips during the session. After you finish, drink another 16 to 32 ounces over the next hour. Adding an electrolyte drink after your session helps replace the sodium, potassium, and magnesium you lose through sweat.

People who support their overall detoxification and hydration habits outside the sauna tend to tolerate sessions better and recover faster. Good daily water intake makes a real difference in how your body handles heat exposure.

Can Infrared Sauna Cause Dehydration?

Yes, infrared sauna can cause dehydration if you do not drink enough water before, during, and after your session. Dehydration is the most common side effect of sauna use, and it is also the most preventable. A 2020 study published in the Journal of Environmental and Public Health found that infrared sauna users produce sweat with a different composition than exercise-induced sweat, including higher concentrations of certain heavy metals. This means you are losing water and trace minerals at the same time. Replacing both fluids and electrolytes after each session is the simplest way to avoid any problems.

What Happens If You Stay in an Infrared Sauna Too Long?

What happens if you stay in an infrared sauna too long is that your body's core temperature rises higher than it should, and your natural cooling system gets overwhelmed. The early warning signs include feeling dizzy, nauseous, or unusually fatigued. Your skin may feel excessively hot and your heart rate may climb beyond what feels comfortable. If you notice any of these signs, the right move is to step out immediately, cool down in a comfortable space, and drink water.

Experts recommend keeping infrared sauna sessions under 45 minutes. Beginners should start at 15 to 20 minutes and gradually increase as their body adapts. The research showing the strongest health benefits used sessions of 20 to 45 minutes, repeated three to five times per week. Going longer does not make the therapy more effective. It just increases the risk of overheating without adding benefits.

A 2021 study published in Complementary Therapies in Medicine measured heart rate increases of 30 to 50 beats per minute during infrared sauna sessions. That level of cardiovascular demand is comparable to brisk walking, which is safe for most people but can become too much if the session drags on past your comfort level.

Is It Normal to Feel Tired After an Infrared Sauna?

Yes, it is normal to feel tired after an infrared sauna session. The heat raises your core body temperature and triggers your cardiovascular system in a way that is similar to moderate exercise. After the session, your body shifts into recovery mode, which naturally produces a calm, drowsy feeling. This is actually one of the reasons infrared saunas are so helpful for people who deal with sleep issues. One study found that 83% of participants reported sleep benefits after a single sauna session, with effects lasting up to two nights.

If the tiredness feels extreme or is accompanied by dizziness, headache, or confusion, that is a sign of dehydration or overheating rather than normal post-session fatigue. The fix is straightforward: shorten your sessions, lower the temperature, and drink more water.

Is Sauna Good for High Cortisol?

Yes, sauna is good for high cortisol. Cortisol is the body's main stress hormone, and chronically elevated levels are linked to anxiety, weight gain, poor sleep, and weakened immune function. Research shows that repeated sauna use leads to a significant decrease in baseline cortisol levels. A study led by Podstawski et al. found that four rounds of sauna sessions with cold breaks significantly reduced cortisol in participants after just a few sessions.

The mechanism involves both the heat itself and the environment. The warmth activates the parasympathetic nervous system, which shifts your body out of "fight or flight" mode. This triggers the release of endorphins and helps regulate stress hormones. The quiet, screen-free setting of a infrared sauna session also forces a mental pause that most people rarely get during their day.

For people dealing with chronic stress, regular infrared sauna use can be a powerful addition to their routine. The cortisol reduction is not just temporary. With consistent sessions, the baseline drops, meaning your body operates from a calmer starting point overall.

Does Sauna Help Anxiety?

Yes, sauna helps anxiety through a combination of cortisol reduction, endorphin release, and nervous system regulation. A study published in the International Journal of Occupational Medicine and Environmental Health found that sauna therapy reduced symptoms of stress and fatigue in workers exposed to high-stress environments. A separate study in the Journal of Human Kinetics confirmed that sauna sessions reduced stress and anxiety levels in athletes.

The Global Wellness Institute reports that the global wellness economy reached $6.8 trillion in 2024, with mental wellness growing at 12.4% annually. The demand for non-pharmaceutical approaches to anxiety is driving more people toward therapies like infrared sauna. The 2024 Laukkanen and Kunutsor comprehensive review linked regular passive heat therapy to improved well-being, less stress, and greater relaxation across the studies examined.

A single session can also improve deep sleep by up to 70%, according to one clinical study. Since poor sleep is both a cause and a symptom of anxiety, this sleep benefit creates a positive cycle that helps break the anxiety loop over time.

What Do 10 Minutes in an Infrared Sauna Do?

What 10 minutes in an infrared sauna does is begin to raise your core body temperature, increase your heart rate, and start the sweating process. Even in a short session, you will notice your skin warming, light perspiration beginning, and a sense of relaxation setting in. Blood flow increases to your muscles and skin, and your body starts to release endorphins.

Ten minutes is enough for a gentle introduction if you are new to infrared saunas or if you have a health condition that requires shorter exposure. It is also a useful length for people using the sauna as a quick recovery tool after a workout. Research from a 2015 study found that even brief heat exposure helped reduce muscle soreness after physical activity.

That said, most of the research documenting significant cardiovascular, detoxification, and skin health benefits used sessions of 20 to 45 minutes. Ten minutes is a good starting point, but working up to longer sessions over time will give you stronger and more lasting results.

Who Should Talk to a Doctor Before Using an Infrared Sauna?

Who should talk to a doctor before using an infrared sauna includes anyone with a known health condition that affects the heart, blood pressure, or the body's ability to regulate temperature. Specifically, this means people with heart disease, uncontrolled high or low blood pressure, diabetes, recent acute injuries, and neurological conditions that impair sweating. Pregnant women should also consult their healthcare provider before using any type of sauna.

Certain medications interact with heat in ways that increase risk. Diuretics increase fluid loss and can make dehydration happen faster. Beta-blockers change how the heart responds to heat. Antihistamines and some antidepressants suppress sweating, which limits the body's ability to cool itself. If you take any of these medications, a conversation with your doctor is important before your first session.

People with pacemakers, defibrillators, or other implanted devices should get medical clearance. Children and older adults should use infrared saunas cautiously because their bodies may be slower to regulate temperature. At our practice in Bedford Hills, we review each person's health background to help them get the safest, most effective experience possible.

What Diseases Does Sauna Prevent?

What diseases sauna helps prevent, based on current research, includes cardiovascular disease, stroke, dementia, and certain respiratory conditions. The landmark Kuopio Ischaemic Heart Disease study published in JAMA Internal Medicine followed 2,315 Finnish men for over 20 years. Those who used a sauna four to seven times per week had a 40% lower risk of all-cause mortality, a 63% lower risk of sudden cardiac death, and a 65% lower risk of Alzheimer's disease compared to those who used one once per week.

A 2024 comprehensive review confirmed these findings and expanded them. Regular passive heat therapy was linked to improved vascular function, reduced arterial stiffness, lower blood pressure, and decreased risk of cardiovascular events, stroke, and cognitive decline. The 2018 systematic review also found that sauna bathing may benefit people with chronic fatigue, fibromyalgia, rheumatoid arthritis, allergic rhinitis, and chronic obstructive pulmonary disease.

It is important to note that sauna therapy is not a substitute for medical treatment. It works best as a complement to a healthy lifestyle that includes proper nutrition, exercise, and regular checkups. Adding salt therapy alongside your infrared sessions can further support respiratory and immune health.

A regular massage routine pairs well with infrared sauna use, too. The heat loosens muscles before or after bodywork, making each treatment more effective.

How to Get the Safest and Best Results From Every Session

Getting the safest and best results from every infrared sauna session comes down to a few basic habits. Hydrate well before, during, and after. Start with shorter sessions if you are new and build up gradually. Keep the temperature comfortable, typically between 110°F and 140°F. Listen to your body. If something feels off, step out.

The 2024 Laukkanen and Kunutsor review emphasized that the greatest health benefits came from consistent, moderate use over time, not from occasional intense sessions. Frequency matters more than duration. Three to five sessions per week at a comfortable pace will do more for your health than one extreme session. The U.S. infrared sauna market was valued at $275 million in 2024 according to Mordor Intelligence, reflecting how many people have made infrared sauna therapy a regular part of their wellness routine.

If you are curious how infrared sauna compares to other heat therapies for respiratory health, we have covered that topic in detail in our post on whether a steam room or sauna is better for your lungs.

Infrared Sauna Side Effects and How to Prevent Them

Side EffectHow CommonCauseHow to Prevent ItDehydrationMost commonSweating without replacing fluidsDrink 16-20 oz water before; sip during; rehydrate afterLightheadednessOccasionalLow blood pressure from heatStand up slowly; cool down gradually after sessionSkin rednessOccasionalIncreased blood flow to skin surfaceTemporary and resolves within 30 minutesFatigueCommonCardiovascular response to heatNormal recovery response; rest and hydrateOverheatingRareSessions too long or temperature too highLimit sessions to 20-45 minutes; start at lower heatElectrolyte lossOccasionalHeavy sweating depletes mineralsDrink electrolyte beverage after session

Sources: Hussain and Cohen 2018 Systematic Review (RMIT University), Mayo Clinic (2024), Journal of Environmental and Public Health (2020), Complementary Therapies in Medicine (2021).

Frequently Asked Questions

Can You Use an Infrared Sauna Too Much?

Yes, you can use an infrared sauna too much if you do not allow your body time to recover and rehydrate between sessions. Experts recommend keeping sessions under 45 minutes and using the sauna three to five times per week for best results. If you notice persistent headaches, elevated resting heart rate, or unusual fatigue, scale back your frequency and consult your healthcare provider.

Is Infrared Sauna Safe for Your Eyes?

Yes, infrared sauna is safe for your eyes during standard sessions at normal temperatures and durations. Far-infrared light, which is the primary type used in most infrared saunas, does not penetrate deep enough to damage the eyes. Some research has noted that long-term, high-intensity exposure to near-infrared light may contribute to lens clouding over time, but this applies to industrial or occupational exposure, not typical sauna use. If you have concerns, closing your eyes during the session adds an extra layer of protection.

Does Infrared Sauna Raise Blood Pressure?

No, infrared sauna does not raise blood pressure in most people. It actually lowers it. A 2017 experimental study found that a single 30-minute sauna session reduced systolic blood pressure from 137 to 130 mmHg and diastolic from 82 to 75 mmHg. A 2022 study showed that eight weeks of consistent use lowered systolic pressure by an average of 12.3 mmHg. People with uncontrolled blood pressure conditions should still consult their doctor before use.

Is Infrared Sauna Safe During Pregnancy?

Infrared sauna use during pregnancy is generally not recommended without a doctor's approval. Elevated core body temperature can affect fetal development, especially during the first trimester. If you are pregnant and interested in heat therapy, talk to your obstetrician first to determine what is safe for your specific situation.

Can Infrared Sauna Affect Fertility?

Infrared sauna can temporarily affect male fertility based on limited research. A small 2013 study found that two sauna sessions per week for three months was associated with lower sperm count and motility. However, these effects were completely reversible once sauna use stopped. Men actively trying to conceive may want to reduce sauna frequency during that time.

Do You Need to Shower After an Infrared Sauna?

You do not need to shower immediately after an infrared sauna, but most people feel better after a lukewarm rinse 10 to 15 minutes later. This gives your body time to cool down naturally first. The rinse helps wash off the salt and toxins released through sweat. Avoid a cold shower immediately after, as the sudden temperature change can cause lightheadedness in some people.

What It All Comes Down To

Infrared sauna side effects are real, but they are mild, temporary, and almost entirely preventable. The research across thousands of participants shows that infrared sauna therapy is safe for the vast majority of healthy adults when basic precautions are followed. Stay hydrated. Keep sessions at a reasonable length. Listen to your body. And talk to your doctor if you have a pre-existing health condition.

At Quantum Healing & Wellness, we guide every member through the process so they get the full benefits of infrared sauna combined with red light therapy in a safe, comfortable setting.

If you have questions or want to schedule your first session, call us at (914) 218-3428.