Heat Exposure Risks in Pregnancy
Medically reviewed by Dr. Lisa Okafor, MD, FACOG · Board-Certified OB-GYN
Content reviewed against published ACOG, NIH, March of Dimes guidelines
Last reviewed:
Your health matters just as much as your baby's. If you are dealing with heat exposure risks in pregnancy, here is what you need to know.
The short answer
Elevated body temperature (hyperthermia) in early pregnancy has been associated with an increased risk of neural tube defects. Hot tubs and saunas, which can raise core body temperature above 101F (38.3C), should be avoided during pregnancy, especially in the first trimester. Warm baths (not hot) at a comfortable temperature are safe and can be soothing.
Key takeaways
- Elevated body temperature (hyperthermia) in early pregnancy has been associated with an increased risk of neural tube defects. Hot tubs and saunas, which can raise core body temperature above 101F (38.3C), should be avoided during pregnancy, especially in the first trimester. Warm baths (not hot) at a comfortable temperature are safe and can be soothing.
- Usually normal when: Taking warm (not hot) baths throughout pregnancy
- Call your doctor if: You have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion
- Varies by age — see the age-by-age breakdown below
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What Parents Should Know
According to ACOG, NIH, March of Dimes guidelines, elevated body temperature (hyperthermia) in early pregnancy has been associated with an increased risk of neural tube defects. Hot tubs and saunas, which can raise core body temperature above 101F (38.3C), should be avoided during pregnancy, especially in the first trimester. Warm baths (not hot) at a comfortable temperature are safe and can be soothing. At First trimester, the first trimester is the most sensitive period for heat exposure because neural tube development occurs in weeks 3-4. Avoid hot tubs, saunas, and steam rooms. Warm baths where your upper body stays above water are fine. If you used a hot tub before knowing you were pregnant, try not to worry - brief exposure is different from prolonged, repeated use. It is generally considered normal when taking warm (not hot) baths throughout pregnancy. However, you should contact your pediatrician promptly if you have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion.
Normal vs. Concerning
By Age
What to expect by age
First trimester
The first trimester is the most sensitive period for heat exposure because neural tube development occurs in weeks 3-4. Avoid hot tubs, saunas, and steam rooms. Warm baths where your upper body stays above water are fine. If you used a hot tub before knowing you were pregnant, try not to worry - brief exposure is different from prolonged, repeated use.
Second trimester
Continue to avoid hot tubs and saunas. Warm (not hot) baths are safe and can help with aches and pains. Avoid overheating during exercise - work out in cool environments, stay hydrated, and stop if you feel overheated. Avoid prolonged sun exposure in extreme heat.
Third trimester
Same guidelines apply. Warm baths can be especially soothing for back pain and swelling. Keep the water comfortable, not hot. If you are unsure about the temperature, it should feel warm and comfortable, not hot enough to make your skin red.
What to Tell Your Pediatrician
- Describe when you first noticed heat exposure risks in pregnancy and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you were exposed to prolonged high heat before knowing you were pregnant.
- Mention if you are unsure about safe temperatures for bathing.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Taking warm (not hot) baths throughout pregnancy
- Mild sweating during exercise that resolves with rest and hydration
- You were exposed to prolonged high heat before knowing you were pregnant
- You are unsure about safe temperatures for bathing
- You have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion
What You Can Do at Home
- Keep track of when you notice heat exposure risks in pregnancy — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that taking warm (not hot) baths throughout pregnancy — this is generally within the range of normal.
- At First trimester, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Prioritize your own rest and nutrition. Accept help when offered, and do not hesitate to reach out to your healthcare provider.
- While monitoring at home, seek immediate care if you have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion.
Related Conditions
Related Resources
Postpartum Recovery Guide
Week-by-week postpartum recovery timeline and warning signs.
Month-by-Month Development
Detailed monthly development guides from birth through 24 months.
When to Call the Doctor
General guide on when to call the pediatrician, visit urgent care, or go to the ER.
Frequently asked questions
Is heat exposure risks in pregnancy normal?
When should I call the doctor about heat exposure risks in pregnancy?
When is heat exposure risks in pregnancy normal?
What causes heat exposure risks in pregnancy?
What should I mention to my pediatrician about heat exposure risks in pregnancy?
Is heat exposure risks in pregnancy normal at First trimester?
Is heat exposure risks in pregnancy normal at Second trimester?
Should I go to the ER for heat exposure risks in pregnancy?
Does heat exposure risks in pregnancy go away on its own?
References
- [1]American College of Obstetricians and Gynecologists. Physical Activity and Exercise During Pregnancy. ACOG, 2020. ACOG
- [2]National Library of Medicine. Maternal Hyperthermia and Neural Tube Defects. Birth Defects Research, 2020. NIH
- [3]March of Dimes. Hot Tubs, Saunas, and Pregnancy. March of Dimes, 2023. March of Dimes
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss Heat Exposure Risks in Pregnancy.
Things to mention
- Describe when you first noticed heat exposure risks in pregnancy and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you were exposed to prolonged high heat before knowing you were pregnant.
- Mention if you are unsure about safe temperatures for bathing.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- You were exposed to prolonged high heat before knowing you were pregnant
- You are unsure about safe temperatures for bathing
Urgent signs to report immediately
- You have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
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Related Resources
Bottom line
Most cases of heat exposure risks in pregnancy are normal. Talk to your pediatrician if you have been in extreme heat and have symptoms of heat exhaustion: heavy sweating, weakness, nausea, rapid heartbeat, or confusion.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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