Feeling the Heat? Your Complete Guide to Pregnancy Temperature Tracking

Pregnancy health is about more than doctor’s appointments. As your baby grows and your body changes, you may find yourself needing to eat differently, to change your exercise routine, and even to rest more than before. You probably expected those changes, but did you expect to your body to get hotter—literally?

If you’ve found yourself breaking a sweat more easily and often, you’re not alone. Your body temperature naturally rises during pregnancy as your hormones shift and your body works harder to support your growing baby. On top of that, rising global temperatures and more intense summer heat waves can leave you struggling to stay cool.

Most people think hot flashes are a sign of menopause, but they are also common during pregnancy. Hot flashes, which cause you to suddenly feel really hot, are uncomfortable but are also usually harmless. But, if your temperature rises too much, whether from spending too much time in the heat or as a sign of sickness, you may need to take special care to protect your health and your baby. When you have a temperature of 100.4°F (38°C) or higher, that’s called a maternal fever. A maternal fever is often a sign of illness or infection or of heat exhaustion—and it can lead to serious problems for you and your baby. That’s why tracking your temperature is important.

The good news is, tracking your temperature is an easy. In this blog, we will explain what causes your temperature to rise and how to know if you’re at-risk, discuss complications to be aware of, share simple steps you can take to keep cool, and give you guidance to help make regular temperature tracking part of your daily routine so you can feel empowered and protected throughout your pregnancy journey.

What Causes Your Temperature to Rise During Pregnancy?

There are a couple natural changes that your body goes through during pregnancy that make your temperature rise. First, as your baby grows, the amount of blood in your body increases and your body needs a lot more energy to function—basically, your body is working extra hard, which causes it to generate more heat. Second, hormone changes, particularly shifts in estrogen and progesterone hormones, affect how your body manages heat.

There are also things outside your body that can affect your temperature. When it’s a hot summer day or an extra warm room, everyone’s body has to work to adjust to that heat. And when you’re pregnant, your body has an even harder time staying cool.

Who Is at Risk?

While anyone can experience a hot day or a sudden fever, there are some things that can make it harder for your body to manage heat. Knowing if you are at risk can help you prepare to keep cool. Here are a few things that can put you more at risk:

• You are under 30 years old.

• You are pregnant with twins, triplets, or more babies.

• You are overweight or obese (talk to a healthcare provider who can help you understand if weight is healthy).

• You have an existing health condition, such as diabetes or a thyroid disorder.

• You have a mental health condition, like anxiety or depression.

• You take certain medications, including some over-the-counter or prescription drugs for high blood pressure.

• You live in an area known for hot weather and high humidity.

In addition to the health issues listed above, there are also social factors, such as race, ethnicity, and income level, that can increase your risk. If you’re part of a racial or ethnic minority group, or if you live in a low-income area, you’re more vulnerable. This is because you’re more likely to deal with chronic stress and less likely to have access to cool, safe spaces. For example, if you live in older urban housing, you may not have air conditioning, or you it may not work well or all the time. Or, if you work outdoors, you may have to be outside during the hottest times of day because of your job. In fact, studies in the US have shown that the risk of heat-related preterm birth and stillbirth is twice as high among Black and Latine individuals as it is among white pregnant individuals (León-Depass and Sakala 2021).

How Can High Temperatures Affect Your Health and Your Baby?

While hot flashes are uncomfortable, they are usually temporary and not harmful. However, when your body temperature is too high for too long, it can harm you and your baby. If you have a fever that is 100.4°F (38°C) or higher, or a fever that doesn’t go away after a day or two, contact your healthcare provider.

How High Temperatures Can Affect Your Health

Illness and infection.

Fevers are often signs of other health issues, such as illness or infections. This is because your body temperature heats up as it works to heal itself. Illnesses and infections can quickly get worse and cause serious complications if they are not treated early.

Dehydration.

When you have a fever or are overheated, your body uses more fluids to stay cool—like how you sweat when you’re really hot—and that can lead to dehydration, which is also not good for you or your baby. For example, being dehydrated can cause contractions, which in some cases can cause you to go into labor early.

Other complications.

Pregnant people who have fevers or spend a lot of time in hot environments (where the temperature is above 87°F or 30.5°C) are more at risk of gestational diabetes (Carty 2026 and Granés et al. 2026) and preeclampsia (Mao et al. 2023). In general, spending a lot of time in hot environments during pregnancy increases the risk of complications by nearly 30%, and often leads to hospitalizations (Khalique 2024).

How High Temperatures Can Affect Your Baby

Birth defects and disorders.

Fevers during pregnancy are linked to higher risk of some birth defects, including breathing issues, heart issues, oral clefts, and neural tube defects (like spina bifida) (Antoun et al. 2021; Dreier, Anderson, and Berg-Beckoff 2014; León-Depass and Sakala 2021). They are also linked with neurodevelopmental disorders.

Premature and low-birth-weight. Spending a lot of time in really hot environments is also linked with preterm labor and delivery (going into labor / having your baby before you reach 37 weeks in your pregnancy) and low-birth-weight babies (babies that are born weighing less than 5 pounds, 8 ounces or 2.5 kilograms) (León-Depass and Sakala 2021 and Konkel 2019). In fact, studies have shown that even spending one day in extreme heat can shorten a pregnancy by as many as five days ((León-Depass and Sakala 2021). Babies who are born too early are more likely to have health issues than those who are born at full-term, as they have not had the chance to fully develop, and many of these babies require special medical care in a neonatal intensive care unit (NICU).

Miscarriage and stillbirth.

In really serious cases, a fever that goes untreated can increase the risk of a miscarriage or stillbirth (León-Depass and Sakala 2021 and Konkel 2019).

While these things may sound scary, knowing how and why these things can happen is the key to avoiding them. And again, if you have a fever that is 100.4°F (38°C) or higher, or a fever that doesn’t go away after a couple days, contact your healthcare provider.

How Can You Beat the Heat?

Keeping cool doesn’t have to be complicated. We’ve identified a nine simple ways that you can avoid overheating and manage your temperature.

1. Get lots of water. Staying hydrated during pregnancy is important for you and your baby. The American College of Obstetricians and Gynecologists recommends pregnant people drink 8 to 12 cups (63 to 96 ounces) of water each day. You can also eat foods with high water content (e.g., cucumbers and watermelon) to reach this goal. You might also want to avoid hot, heavy food and beverages, as these can increase body temperature.

2. Dress for different temperatures.

Wear lightweight layers that you can easily add or remove clothing throughout the day. Choose breathable natural fibers, such as cotton and linen, in comfortable, loose-fitting styles to help keep air moving around your body. And, if you’ll be spending time outdoors, wear a wide-brimmed hat that can help shade you from the sun.

3. Change up your exercise routine.

Staying active during pregnancy is great for your physical and mental health. But swapping high-intensity for low- to medium-intensity workouts (such as swimming, walking, and yoga) and working out in air-conditioned or other well-ventilated, cool spaces is important for preventing your temperature from rising to dangerous levels.

4. Rest when your body tells you to.

If you have a fever because of an illness or infection, resting allows your body to save energy for healing. If you start feeling warm because you’re working out too hard or because it’s really hot outside, slow down or take a break.