Heat waves are becoming more frequent and intense and can occur in any season. For most people, a hot day means seeking shade, drinking extra water, and staying cool indoors. But for pregnant individuals, extreme heat can be especially dangerous, for both mom and baby.
Heluna Heath’s Research and Evaluation team, in collaboration with members of the American Public Health Association’s (APHA) Children’s Environmental Health Committee, has developed a new set of infographics to help pregnant individuals and their healthcare providers understand these risks and take action. Here’s what you need to know:
The Hidden Dangers of Heat During Pregnancy
Pregnancy already puts extra demands on the body. Your heart works harder, your blood volume increases, and your core temperature naturally runs a little higher. When you add extreme heat and humidity to the mix, the body can struggle to cope, and the consequences can be serious.
Hot and humid weather during pregnancy has been linked to:
- Dehydration: The body needs more fluids during pregnancy, and heat accelerates fluid loss through sweat.
- Heat illness and heat stroke: Pregnant individuals are more vulnerable to overheating, and heat stroke is a medical emergency.
- High blood pressure and preeclampsia: Heat can trigger dangerous spikes in blood pressure, increasing the risk of this serious pregnancy complication.
- Reduced blood flow to the placenta: When the body overheats, blood is redirected to the skin to cool down, which can reduce the supply reaching the placenta.
- Mental health challenges: Extreme heat has been associated with increased anxiety, depression, and psychological stress during pregnancy.
- Premature birth or low birth weight: Extreme heat exposure has been linked to babies born too early or too small.
As heat waves grow more common due to climate change, these risks affect more pregnant people, even in regions that don’t normally have hot weather.
Know the Warning Signs
One of the most important things you can do is learn to recognize the difference between moderate heat illness and heat stroke because the response is different for each.
Moderate heat illness may look like: heavy sweating, clammy skin, muscle cramps, headache, dizziness, weakness, or fatigue. If you experience these symptoms, the priority is to cool your body down. Move to a shaded or air-conditioned space, apply cool cloths, drink water, and loosen your clothing. If symptoms don’t improve within an hour, seek emergency care.
Heat stroke is a medical emergency. Warning signs include a fever above 102°F, confusion or slurred speech, nausea or vomiting, and loss of consciousness. If you or someone around you shows these signs, call 911 immediately. Do not give fluids to someone who is unconscious.
When in doubt, always err on the side of getting medical help. It’s always better to be seen and sent home than to wait too long.
How to Protect Yourself on Hot Days
The good news is that there are straightforward, practical steps you can take to stay safer during heat waves, including:
Stay Cool. Limit outdoor activity during the hottest parts of the day (typically midday to late afternoon). Wear loose, light-colored clothing, a wide-brimmed hat, and sunscreen. Take cool showers. Spend time in air-conditioned places — a library, a mall, or a community cooling center if you don’t have AC at home.
Stay Hydrated. Drink plenty of water or electrolyte-replenishing drinks throughout the day; don’t wait until you feel thirsty. Avoid carbonated beverages, energy drinks, and alcohol, all of which can contribute to dehydration.
Stay Connected. Sign up for local weather alerts so you know when a heat advisory or extreme heat warning is in effect. Make sure a partner, friend, family member, or neighbor is checking in with you on very hot days and knows to help you access medical care if needed.
Seek Care When Needed. Call 911 or go to the emergency room if you feel very sick, or if moderate heat illness symptoms persist for more than an hour. Don’t tough it out; heat can escalate quickly during pregnancy.
Talk to Your Doctor: Create a Heat Action Plan
One of the most valuable things you can do before a heat wave hits is have a conversation with your OB, midwife, or other healthcare provider about developing a personalized heat action plan. This is especially important if you take any medications, since some drugs can make your body more sensitive to heat or worsen dehydration.
Some questions to bring to your next appointment:
- “I’d like to make a plan to protect myself and my baby on very hot days — can you help me put one together?”
- “Do any of my medications make me more sensitive to heat or more likely to get dehydrated?”
- “How much water should I be drinking on hot days?”
For Healthcare Providers: Starting the Conversation
Providers play a critical role in helping pregnant patients understand and prepare for heat risks, and the conversation doesn’t have to be complicated. Research shows that many patients don’t realize how heat can affect their health during pregnancy, even if they generally feel well on hot days.
Here are a few suggested conversation starters to help clinicians raise the topic naturally during prenatal visits:
- “Hot days can be dangerous for pregnant women, even if you normally feel fine. Let’s make a plan to keep you safe on hot days.”
- “As it gets hotter, I want to make sure you and your baby stay healthy. Let’s talk about heat safety at home and at work.”
- “Some medications may make you more dehydrated or sensitive to heat. Let’s make a plan for hot days to help you stay healthy.”
It’s also worth asking patients whether they have reliable access to air conditioning at home, since lack of AC is one of the biggest risk factors for heat-related illness — and one that patients may not volunteer without being asked.
Two resources are available to help structure these conversations: the CDC CHILL’D-Out Assessment Tool, designed to help providers assess heat-related risk, and the AmeriCares Sample Heat Action Plan Template that providers and patients can complete together. Some resources for healthcare providers are available from the Society for Maternal-Fetal medicine in a podcast addressing heat exposures during pregnancy and from the Arizona Department of Health Services with this list of medications that may increase the risk of heat illness.
Resources Available in English and Spanish
Heat waves aren’t going away, but with the right knowledge and a proactive plan, you can protect yourself and your baby. Share these resources with someone who’s pregnant, a new parent, or a healthcare provider in your community. Awareness saves lives.
