Heat and Pregnancy: What Pharmacists Need to Know

Over the last few years, record-high temperatures have been recorded in many parts of the United States.¹ Extreme heat events, or a series of hotter-than-average days, are becoming more common and are expected to happen more often in the future.¹ As pharmacists, we need to recognize and consider the specific impact heat may have on our patients who are pregnant. Women are already at increased risk of physical, sexual, and domestic violence in the aftermath of climate-driven disasters.² Heat further exacerbates these existing health disparities as pregnant individuals, infants and children, older adults, and those with chronic conditions or taking certain medications experience higher rates of heat-related illnesses.^1,3,4 Social determinants of health, such as geographic location, socioeconomic status, and food security, can amplify the impact of heat on health.⁵ For example, risk factors such as working in a hot environment, living in an area with limited shade, and not having air conditioning at home can further increase their vulnerability.^1,4,6

Pregnancy is a physically demanding process, and pregnant patients’ bodies often have to compensate more to take care of themselves and the fetus.⁵ The heart often is working harder, producing more blood volume and a faster heart rate, in order to dissipate the internal heat.⁷ In addition, hotter temperatures leading to dehydration further interferes with one’s ability to cool through sweating.⁵ It is critical that one’s body temperature does not exceed 102℉, as this could trigger uterine contractions or early labor in the later stages of pregnancy.^8,9 Even as little as one day of high heat exposure can have significant consequences such as an increased risk of high blood pressure disorders, seizures, and other pregnancy complications.^6,7

Not only is the pregnant individual affected, but so is the developing fetus. Heat exposure has been linked to preterm births, stillbirths, low-birthweight infants, and birth defects.^7,9 Preterm birth, or delivery before 37 weeks of gestation, is a leading cause of infant mortality in the US and can lead to long-term health challenges.¹⁰ Infants born prematurely or with complications such as congenital heart defects or impaired brain and lung development often have trouble breathing, eating, and fighting sickness.⁹ Consequently, as they get older, they may have growth, behavior, and cognition issues, forcing families to endure financial strain and emotional stress.⁹

Pharmacists in particular can play a vital role in raising awareness about the consequences of heat exposure among pregnant patients. The CDC recommends steps clinicians should take to mitigate the impact of heat on pregnant patients and has a one-page, patient-friendly handout containing key information to share with patients. Although pharmacists need to provide counseling tailored to each individual, staying hydrated with water is an important protective measure to share.^5,8 Other drinks such as electrolyte-filled fluids may replenish minerals lost through sweating, but patients should check the sodium content.⁸ Pregnant patients should avoid beverages such as caffeinated drinks and sugary sodas, as they may not provide enough hydration.⁸

Eating water-rich food such as fruits and vegetables can help patients achieve their recommended amount of water each day.⁵ Medication management is critical as well, as some medications such as antihistamines, antidepressants, and beta-blockers may increase one’s heat sensitivity or impact one’s fluid balance.^7,11 Pharmacists should carefully assess pregnant patients’ medication profiles and make sure patients are aware of these possible risks and appropriate action steps. Pharmacists should also counsel patients on recognizing symptoms of heat exhaustion such as headache, dizziness, and extreme thirst as well as severe symptoms such as confusion, nausea, or slurred speech, which requires immediate medical attention.⁸ Some of these symptoms may get confused with common pregnancy symptoms, further supporting the need for more patient education.⁸

Additional education should focus on modifying one’s home to reduce heat exposure.⁶ For example, maintaining a cool environment through air conditioning, blackout curtains, window reflectors, or proper insulation can keep the heat out.⁶ Fans should only be used when indoor air temperatures are less than 90°F.⁵ For those who do not have access to air conditioning at home, finding public cooling spaces such as libraries or mall outlets is highly recommended. Moreover, monitoring the air quality index (AQI) is also important, as air pollution is worse on hotter days.⁷ If the AQI exceeds 100, patients should take protective action.⁷ Some behavioral interventions include avoiding strenuous activities during peak heat hours, wearing breathable clothing, and avoiding spending long periods of outdoor exposure on hot days.⁷

Pharmacists can share valuable community tools and public health resources with patients. The CDC Heat & Health Tracker and National Weather Service HeatRisk tools provide real-time updates on heat risk and air quality. This is important because not all jurisdictions include heat health information on their websites, and of those that do, very few specifically highlight risks in pregnancy.¹² Pharmacists should also encourage patients to get extreme heat alerts (if available) sent to their phone or utilize resources such as 211 to find public cooling centers.⁵ Regulations such as the Pregnant Workers Fairness Act (PWFA) may provide workplace accommodations such as increased breaks to cool down, hydrate, and use the bathroom are critical for pregnant individuals exposed to heat at work.¹³

Rising temperatures are becoming an increasingly significant threat to pregnant patients and their infants and children. Pharmacists can play a key role in reducing heat-related illness in these vulnerable populations through patient education, medication management, and raising awareness about accessible tools.

Read the other installments:
Heat and Human Health: What Pharmacists Need to Know

Heat and Older Adults: What Pharmacists Need to Know

Heat and Medications: What Pharmacists Need to Know

REFERENCES

1. U.S. Environmental Protection Agency. Climate change and extreme heat: What you can do to prepare. EPA 430-R-16-061. October 2016. Accessed April 20, 2026. https://www.epa.gov/sites/default/files/2016-10/documents/extreme-heat-guidebook.pdf

2. Sbiroli E, Geynisman-Tan J, Sood N, et al. Corrigendum to "Climate change and women's health in the United States: Impacts and opportunities" [J Clim Change Health 8C (2022) 100169]. J Clim Chang Health. 2024;20:100331.doi:10.1016/j.joclim.2024.100331

3. Etzel RA, Weimann E, Homer C, et al. Climate change impacts on health across the life course. J Glob Health. 2024;14:03018. doi:10.7189/jogh.14.03018

4. Centers for Disease Control and Prevention. Clinical overview of heat. September 18, 2025. Accessed April 20, 2026. https://www.cdc.gov/heat-health/hcp/clinical-overview/index.html

5. U.S. Environmental Protection Agency. Heat and pregnancy. August 13, 2025. Accessed April 20, 2026. https://www.epa.gov/children/heat-and-pregnancy

6. California Department of Public Health. Safe pregnancies in extreme heat. May 27, 2025. Accessed April 20, 2026. https://www.cdph.ca.gov/Programs/CFH/DMCAH/Pages/Health-Topics/Safe-Pregnancies-in-Extreme-Heat.aspx

7. Centers for Disease Control and Prevention. Heat and pregnancy. June 25, 2024. Accessed April 20, 2026. https://www.cdc.gov/heat-health/risk-factors/heat-and-pregnancy.html

8. Rose A.Staying safe in the heat during pregnancy. Mayo Clinic Health Systems. July 9, 2024. Accessed April 20, 2026. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/staying-safe-in-heat-during-pregnancy

9. Konkel L. Taking the heat: Potential fetal health effects of hot temperatures. Environ Health Perspect. 2019;127(10):102002. doi:10.1289/EHP6221

10. Centers for Disease Control and Prevention. Preterm birth. November 8, 2024. Accessed April 20, 2026. https://www.cdc.gov/maternal-infant-health/preterm-birth/index.html

11. Centers for Disease Control and Prevention. Heat and medications: Guidance for clinicians. September 18, 2025. Accessed April 20, 2026. https://www.cdc.gov/heat-health/hcp/clinical-guidance/heat-and-medications-guidance-for-clinicians.html

12. Stassen R, Zottarelli LK, Rowan P, et al. Extreme heat and pregnancy: A content analysis of heat health risk communication by US public health agencies. Disaster Med Public Health Prep. 2024;18:e71. doi:10.1017/dmp.2024.44

13. U.S. Equal Employment Opportunity Commission. What you should know about the Pregnant Workers Fairness Act. Accessed April 20, 2026. https://www.eeoc.gov/wysk/what-you-should-know-about-pregnant-workers-fairness-act