Is Saunas Safe During Pregnancy?
A research-backed, plain-English answer plus the modifications and warning signs that matter.
The short answer
Sauna temperatures rapidly raise core body temperature.
What the research and physiology say
Saunas raise your core body temperature even faster than hot tubs because of the dry, very hot air (typically 150-195°F / 65-90°C). Sweating is your body's main way to cool down, but in a sauna the air is so hot that sweat cannot evaporate fast enough to keep your core cool. Within 10-15 minutes most people see core temperature climb 1-2°F (0.5-1°C). As with hot tubs, sustained core temps above 102°F (39°C) during early pregnancy are associated with increased risk of neural tube defects and other developmental concerns. Later in pregnancy, sauna use can cause fainting (your blood pressure already runs lower in pregnancy, and heat lowers it further) and can trigger contractions through dehydration and electrolyte shifts. Steam rooms have the same risks as dry saunas.
How to make it safer (or skip it well)
There is no safe way to use a traditional sauna during pregnancy. If you find a sauna marketed as "pregnancy-safe" because the temperature is lower (some are 120°F), that is still high enough to raise core temperature meaningfully when combined with sustained exposure. Skip all sauna types — dry Finnish saunas, steam rooms, infrared saunas, sauna domes, and any other heat-immersive setting. Stick to comfortably warm baths at home (under 100°F). Brief warm showers are fine and do not raise core temperature.
Warning signs — stop and call your provider
If you used a sauna before knowing you were pregnant, mention it to your provider but a single short exposure is unlikely to harm. Any of these after heat exposure needs urgent attention: dizziness, fainting, racing heart, contractions, vaginal bleeding, or reduced fetal movement.
What the medical bodies say
ACOG, the CDC, the American Pregnancy Association, and most national obstetric organizations advise against sauna use during pregnancy. Finnish sauna culture historically allowed pregnant women in low-temperature saunas with strict time limits, but modern medical guidance even in Finland recommends caution especially in the first trimester.
For your partner or support person
If you have a spa membership or sauna routine, your partner can take the sauna while you enjoy a cool pool, walking massage, or relaxation room. Spas usually have plenty of non-heat options.
Common misconceptions
People think saunas detoxify and that helps pregnancy. There is no evidence saunas remove pregnancy-related toxins, and the heat exposure outweighs any theoretical benefit. Another myth: a quick visit is fine. Even brief sauna sessions raise core temperature quickly because the air is so much hotter than body temperature. A third myth: drinking water while in the sauna prevents overheating. Hydration helps but does not prevent core temperature rise.
Things to watch for
Skip all sauna types — dry, steam, infrared.
Safer alternatives
Cool/warm bath; spa treatments that don't raise core temp.
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