Are Hot Tubs and Saunas Safe During Pregnancy?

A hot tub or sauna sounds like exactly what an achy pregnant body deserves, and the good news is that warmth itself is not off the menu, only the extremes of it. The concern is heat: raising your core body temperature too high, especially early in pregnancy. Here is the one rule worth remembering, and all the cozy things still very much yours.

Are hot tubs safe during pregnancy?

Hot tubs are generally advised against during pregnancy. The concern is not the water itself but heat: soaking in a hot tub can push your core body temperature into a range linked to birth defects, especially early on. A safe swap is a warm (not hot) bath with your upper body out of the water.

Why heat is the concern

Sitting in very hot water or a hot, steamy room can raise your core body temperature. A sustained high core temperature in early pregnancy (often described as overheating, similar to a high fever) has been associated with a higher risk of neural tube defects and other problems. Hot tubs are a particular concern because the water stays hot and your body cannot cool down by sweating the way it does in a sauna.

How the risk changes by trimester

The first trimester is the key window. These early weeks are when your baby’s neural tube (the beginnings of the brain and spine) is forming, and studies have linked a raised core body temperature in this stretch to a higher chance of neural tube defects. ACOG and Mayo Clinic both point to heat exposure early in pregnancy as the main worry, which is why the standard advice is to skip hot tubs and saunas from the start.

Later in pregnancy the emphasis shifts. Neural tube development is finished by then, but heat can still leave you overheated, dizzy, or faint, and it can drop your blood pressure at a point when you may already feel warmer and more lightheaded than usual. The caution stays, the reason just changes from your baby’s early development to your own comfort and safety.

Temperature and time: the numbers that matter

You only need one rule here: keep your core body temperature below about 102.2F (39C). A hot tub cannot help you do that, because it is commonly set around 104F (40C), hotter than the ceiling itself, and Mayo Clinic notes that more than about 10 minutes in one can raise your body temperature above 101F (38.3C). A warm bath you can control; a hot tub is built to stay hot.

What you can still do safely

• Hot tubs and jacuzzis: best avoided in pregnancy, especially the hot, prolonged soaks they are designed for.
• Saunas and steam rooms: generally advised against, for the same overheating reason.
• Hot baths at home: keep the water warm rather than hot, keep it short, and keep your shoulders or chest out so you are not fully immersed in heat. A warm bath that does not make you sweat or feel flushed is fine.

A simple test: if the water or room would make you sweat or feel uncomfortably hot, it is too hot for now.

And if what your body is actually asking for is relief rather than heat, you have lovelier options than a jacuzzi anyway. A prenatal massage gives you the melt-into-the-table feeling with none of the temperature worry, and a good pregnancy pillow quietly does more for nighttime aches than any soak ever managed.

Listen to your body

Pregnancy can make you feel warmer and more lightheaded anyway, and heat can drop your blood pressure and make you dizzy. If at any point you feel too warm, dizzy, faint, or unwell, get out, cool down, and have some water. There is no prize for toughing it out.

What if I used a hot tub before I knew I was pregnant?

This is one of the most common worries, and it is worth saying plainly: a single soak before you knew you were pregnant is not a reason to panic. The concern is with repeated or prolonged overheating, not one short exposure, and plenty of people who had a warm bath or a brief hot tub sit early on go on to have healthy pregnancies. Mention it at your next appointment so your provider has the full picture, and lean on the safer warm-water habits from here on. If it helps to think through other early exposures too, our pregnancy-safe ingredients guide takes the same calm, one-thing-at-a-time approach.

When to talk to your provider

Check in if you have questions about warm-water exercise classes, which are generally kept at a safe temperature but are worth confirming, or if you ever feel faint or unwell after any heat exposure. Your provider would rather answer a small question early than field a bigger worry later.

Every pregnant woman I know eventually lands on one reliable way to unwind: the warm 8pm bath, the feet-up podcast hour, the slow walk after dinner. If you have found yours, pass it on below. A newly pregnant reader is scanning this page right now, wondering what is left, and your answer is the encouragement she came for.

Frequently asked questions

Can I use a hot tub in the first trimester?

Most guidance is to avoid hot tubs in the first trimester, since raising your core temperature too high early on is linked to a higher risk of certain birth defects. Hot tubs stay hot and your body cannot cool down easily, so they are best skipped. Check with your provider.

Is a warm bath safe during pregnancy?

Yes, a warm bath is fine as long as the water is comfortably warm rather than hot. Keep it short, keep your shoulders or chest out so you are not fully immersed, and get out if you start to sweat or feel flushed. A bath that does not overheat you is safe.

I used a hot tub before I knew I was pregnant, should I worry?

Try not to worry, and mention it to your provider so they can reassure you. Many people use hot tubs before they realize they are pregnant. The concern is repeated or prolonged overheating, so a single soak is worth discussing but not a reason to panic. Your provider can answer your questions.

How hot is too hot for a pregnant woman?

A simple test is that if the water or room would make you sweat or feel uncomfortably hot, it is too hot for now. Pregnancy already makes you feel warmer, so aim for comfortably warm rather than steaming, and get out if you feel dizzy, faint, or unwell.

Are saunas safe during pregnancy?

Saunas and steam rooms are generally advised against in pregnancy, for the same overheating reason as hot tubs. Raising your core temperature too high, especially in the first trimester, is the concern. If you want to warm up, a comfortably warm bath is the safer choice. Check with your provider.

Medical Disclaimer: This article is for general educational purposes only and is not medical advice, and it does not replace guidance from your doctor or midwife. Always confirm what is right for you with a qualified professional. If you think you may be experiencing a medical emergency, contact your local emergency services right away.

Sources

• American College of Obstetricians and Gynecologists (ACOG). “Physical Activity and Exercise During Pregnancy and the Postpartum Period.” 2020.
• Mayo Clinic. “Pregnancy and hot tubs: What’s the risk?” 2024.
• Organization of Teratology Information Specialists (MotherToBaby). “Fever/Hyperthermia.” Fact sheet, 2025.
• National Health Service (NHS). “Things to avoid in pregnancy: saunas and hot tubs.” 2024.