Pregnancy is a time of careful choices. You've likely already adapted your diet, exercise routine, and lifestyle—and heat exposure is no exception. If you've been a regular sauna user before pregnancy, or if you're considering infrared sauna therapy during this significant life stage, understanding what the American College of Obstetricians and Gynecologists (ACOG) recommends is essential.
This guide separates evidence-based guidance from misconception, focusing specifically on infrared sauna use in pregnancy, the science behind overheating concerns, and what current medical organizations recommend.
Understanding ACOG's Overheating Caution in Pregnancy
ACOG's primary concern with heat exposure during pregnancy—whether from hot tubs, traditional saunas, or infrared saunas—centers on maternal core body temperature elevation, particularly during the first trimester.
Why Core Temperature Matters
The concern is not about comfort or minor warmth. Research has suggested that sustained elevations in core body temperature, especially above 101–102°F (38.3–38.9°C), during early pregnancy may be associated with increased risk of certain birth defects. The critical window is typically the first eight to twelve weeks of gestation, when fetal neural tube development is most active.
ACOG's recommendation reflects a precautionary principle: because the consequences of excessive heat exposure during organogenesis are potentially serious, even if the absolute risk is small, the organization advises pregnant people to avoid sources of intense heat that could elevate core temperature significantly. infrared sauna while pregnant: safety guide sauna safety tips
How This Applies to Infrared Saunas Specifically
Infrared saunas operate differently from traditional Finnish dry saunas. Traditional saunas heat the air and surrounding environment to very high temperatures (160–195°F / 70–90°C), which rapidly elevates core body temperature through convection and radiation. Infrared saunas use infrared light to penetrate the skin and heat the body more directly, often at lower ambient temperatures (around 120–150°F / 49–65°C).
Despite this difference in mechanism, the endpoint is the same: if you remain in an infrared sauna long enough, your core body temperature will rise. A 2022 study showed that in healthy women, infrared sauna exposure raised tympanic (ear) temperature more significantly during the sauna session compared to exercise or a thermoneutral control (Hussain et al., 2022). This demonstrates that infrared saunas are indeed capable of producing meaningful thermal stress, which is why ACOG's caution applies to both modalities.
The Science Behind Hyperthermia and Early Pregnancy
Animal and Observational Evidence
The primary evidence linking maternal hyperthermia to birth defects comes from animal studies and observational epidemiological data, rather than controlled human trials (which would be unethical to conduct). These studies, conducted over several decades, have consistently shown that maternal core temperatures sustained at or above 101.3°F (38.5°C) during the first trimester increase the risk of neural tube defects and other congenital anomalies.
Human epidemiological studies have supported this correlation, linking fever and heat exposure in the first trimester to increased rates of cleft palate, cardiac defects, and developmental delay. The effect appears dose-dependent: higher temperatures and longer duration of exposure correlate with greater risk.
Why the First Trimester Is Most Critical
During weeks 3–8 of gestation, the fetus undergoes rapid organogenesis. The neural tube—which becomes the brain and spinal cord—is forming, and the heart is developing. Heat stress during this window may disrupt gene expression and cellular differentiation, leading to structural defects that become apparent later.
After the first trimester, while heat remains a stressor, the absolute risk of malformation decreases significantly because organogenesis is largely complete. However, ACOG still recommends caution throughout pregnancy, as heat stress can affect placental function, fetal heart rate, and maternal fluid balance.
ACOG's Specific Recommendations on Saunas and Hot Tubs
The Core Guidance
ACOG advises pregnant individuals to avoid prolonged sauna and hot-tub use, with these key points:
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Hot tubs: Avoid altogether, or limit to very short periods (a few minutes) at moderate temperatures (not exceeding 100°F / 37.8°C). Standard hot tubs maintained at 104°F (40°C) or higher are considered too warm.
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Saunas: Traditional saunas should be avoided or used only very briefly and at lower temperatures, with immediate exit if you feel uncomfortably warm.
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Core temperature threshold: Maintain core body temperature below 101°F (38.3°C) throughout pregnancy.
The recommendation is intentionally conservative because:
- Individual variation: Not all people respond identically to heat; pregnancy itself alters thermoregulation.
- Difficulty in self-monitoring: You cannot easily gauge your core body temperature in real time.
- Unknown safety margin: The exact threshold at which risk begins is not precisely known, so a safety buffer is prudent.
Infrared Saunas and ACOG Guidance
ACOG does not distinguish between infrared and traditional saunas in its guidance. Both are included in the general recommendation to avoid prolonged heat exposure. Because infrared saunas can elevate core temperature significantly (Hussain et al., 2022), they should be treated with the same caution.
If a pregnant individual chooses to use an infrared sauna despite these recommendations, the same rules apply:
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Limit duration: No more than 10–15 minutes maximum.
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Keep temperature moderate: Below 110°F (43°C) ambient temperature.
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Exit immediately if uncomfortable: Dizziness, unusual fatigue, or excessive sweating warrant prompt exit.
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Stay hydrated: Drink water before, during, and after.
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Discuss with your OB-GYN first: Do not assume it is safe without explicit clearance.
Managing Heat Exposure During Pregnancy: Safe Alternatives
If you've enjoyed sauna use before pregnancy and are struggling with the restriction, several alternatives can provide relaxation and some of the wellness benefits without the overheating risk:
Warm (Not Hot) Water Immersion
A warm bath or shower at body-safe temperatures (around 98–100°F) provides muscle relaxation and psychological benefits without the rapid core temperature rise of a sauna. Limit duration to 15–20 minutes and avoid very hot water.
Gentle Yoga and Stretching in a Comfortable Environment
Low-impact movement in a room-temperature or slightly warm (not heated) setting addresses muscle tension, supports circulation, and promotes relaxation without heat stress.
Massage and Physical Therapy
Prenatal massage from a licensed therapist trained in pregnancy care can relieve tension without any overheating risk.
Cold and Contrast Approaches
Some women find that cool water immersion (safe in pregnancy if not extreme) or contrast therapy—alternating warm and cool water at moderate temperatures—offers refreshment and supports circulation without sustained hyperthermia.
Breathing and Meditation Practices
The relaxation and stress-reduction benefits often attributed to sauna use can be realized through guided breathing, progressive muscle relaxation, and meditation, with no physical risk.
What to Do If You've Been Exposed to Heat During Early Pregnancy
If you used a sauna or hot tub before realizing you were pregnant, or early in pregnancy before reading this guidance, do not panic. A single, brief exposure is unlikely to cause harm. The concern is with repeated, prolonged exposure that sustains elevated core temperature.
If you have specific concerns:
- Contact your OB-GYN: Describe the exposure (temperature, duration, how recently).
- Be honest about symptoms: Report any dizziness, unusual fatigue, or other symptoms that occurred.
- Discuss your baseline risk: Your provider can assess your individual risk factors and recommend monitoring if appropriate.
In most cases, isolated heat exposure in early pregnancy does not result in adverse outcomes. ACOG's caution is precautionary, not a guarantee of harm from occasional exposure.
The Broader Context: Sauna Use and Reproductive Health
While ACOG recommends avoiding saunas during pregnancy, it is worth noting that sauna use in general is associated with several health benefits for non-pregnant individuals. Studies of traditional Finnish sauna use, for instance, have linked regular sauna bathing to reduced cardiovascular disease risk, improved hypertension control, and lower all-cause mortality (Laukkanen et al., 2015; Laukkanen et al., 2018). However, these long-term health benefits do not apply during the pregnancy window, when the acute risk of hyperthermia outweighs any speculative benefit.
If you are planning pregnancy, establishing a sauna habit before conception is reasonable (pending discussion with your provider). Once pregnant, the recommendation is to pause sauna use and resume postpartum, if desired.
Frequently Asked Questions
Q: Is infrared sauna safer than a traditional sauna during pregnancy?
A: Both infrared and traditional saunas can elevate core body temperature, and ACOG's caution applies to both. Infrared saunas may operate at lower ambient temperatures, but they still produce meaningful thermal stress (Hussain et al., 2022). Neither is recommended during pregnancy. Always consult your OB-GYN before using any sauna while pregnant.
Q: What if I use a sauna at a very low temperature or for just a few minutes?
A: Brief exposure at very moderate temperatures (below 100°F ambient) poses less risk than prolonged use at high heat. However, the safest approach is avoidance. If you do choose to use a sauna during pregnancy—ideally only after discussing with your OB-GYN—keep duration under 10 minutes, maintain ambient temperature below 110°F, and exit immediately if you feel overheated.
Q: Can I use an infrared sauna in my second or third trimester?
A: While absolute risk decreases after the first trimester, ACOG still recommends avoiding saunas throughout pregnancy. Heat stress in later pregnancy can affect placental blood flow and fetal heart rate. The precautionary approach is to avoid sauna use for the entire duration of pregnancy.
Q: Are there any sauna benefits specific to pregnancy that might justify the risk?
A: No. While sauna use in non-pregnant populations has been linked to cardiovascular benefits and stress reduction, these do not outweigh the documented risk of hyperthermia during pregnancy. Safer alternatives like warm baths, prenatal massage, and gentle movement provide similar relaxation benefits without overheating risk.
Q: What should I do if I'm addicted to sauna use and struggle with the restriction?
A: This is a valid concern. If sauna use was a significant part of your wellness routine, its temporary absence during pregnancy can feel like a loss. Consider:
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Reframe the timeline: Pregnancy is temporary (9 months); sauna use can resume postpartum.
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Explore alternatives: Warm baths, massage, yoga, and breathing practices offer many of the same psychological and stress-relief benefits.
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Discuss with your provider: If you have strong reasons for wanting heat therapy, your OB-GYN may be able to suggest individualized adaptations or alternatives suited to your specific needs.
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Plan ahead: Knowing you'll resume sauna use postpartum can make the restriction feel less permanent.
The Bottom Line: Safety, Precaution, and Peace of Mind
ACOG's recommendation to avoid saunas and hot tubs during pregnancy is grounded in decades of research linking maternal hyperthermia to fetal risk. While the absolute risk of any individual exposure is small, and while sauna use itself offers health benefits to non-pregnant individuals, the precautionary principle—avoiding a modifiable risk when the stakes are highest—is sound medical practice.
Infrared saunas, despite their lower ambient operating temperatures, still raise core body temperature significantly and are included in this caution. For the nine months of pregnancy, the choice to avoid sauna heat is a small sacrifice in service of the safest possible environment for your developing baby.
If you have used a sauna during early pregnancy, do not assume the worst—isolated brief exposures are unlikely to cause harm. If you wish to use a sauna despite this guidance, discuss your specific situation with your OB-GYN. And once pregnancy is behind you, saunas and their documented wellness benefits will be waiting for you to enjoy again.
Disclaimer: This article is educational and does not substitute for medical advice. Always consult your obstetrician or midwife regarding heat exposure, sauna use, or any other concerns during pregnancy. Individual risk factors and medical history may influence recommendations specific to you.