How to Prevent Overheating in Pregnancy

How to Prevent Overheating in Pregnancy

tips for avoiding overheating in pregnancy

  Verywell / Hilary Allison

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Pregnancy can be hot. In fact, research has shown that a pregnant person’s blood volume increases by 45% on average. The effort it takes to carry around an extra 20 to 30 pounds means your pregnant body is bound to get hot because of all the work it is expending. All of that work means that you might sweat more and dehydrate more easily.

Even your heart has to work harder. The sharpest rise in cardiac output occurs at the beginning of the first trimester and it continues to increase into the second trimester. By the end of the second trimester cardiac output may be up by 45%.

Consequently, with all these changes it is only natural that your body is working harder to cool your entire system. For this reason, it can be particularly easy for a pregnant body to overheat quickly. And, when this happens, both you and your baby could be at risk for complications.

What Is Considered Overheating?

When your temperature rises to 104 degrees Fahrenheit, this is considered overheating or hyperthermia. Typically, this temperature is caused by dehydration, spending too much time in hot weather, or sitting for too long in a hot bath. But, sometimes there is an underlying medical condition an illness like the flu, or an infection that causes such a high temperature.

Either way, overheating is not something you should ignore. Regardless of the root cause of your elevated temperature, when your body overheats, it is important to seek medical attention right away. There are too many risks associated with overheating to simply ignore your high temperature and hope that drinking some water and sitting in front of a fan will bring it down.

Symptoms of Overheating

Sometimes pregnant people will overheat and not even realize that their internal body temperature is elevated, especially on a hot summer day. Still, it is important to pay attention to how you are feeling. Getting overheated while pregnant can be a big deal, especially if the high temperature is prolonged. Here are some signs that your body may be overheating:

  • Temperature over 103 degrees
  • Hot, dry, red, or cold and clammy skin
  • Fast pulse
  • Headache
  • Experiencing dizziness or like the room is spinning
  • Feeling sick to your stomach or vomiting
  • Confusion
  • Loss of consciousness
  • Sweating profusely that does not stop despite attempts to cool off
  • Feeling weak, tired, or lethargic

In extreme cases, you may even begin to vomit or even experience painful contractions. If this happens, do not delay in getting medical attention right away.

Causes of Overheating in Pregnancy

While there are any number of reasons why you may begin to overheat, there are some factors that are more likely to elevate your body's temperature than others. For this reason, it is extremely important that you use caution when you are pregnant, especially when it is hot outside or you are in a warm area. Some examples of contributing factors include:

  • Hot weather
  • Being physically active for an excessive amount of time, especially in hot conditions
  • Walking or hiking for a long time on a very hot day
  • Participating in strenuous exercises for an extended period of time
  • Sitting in a sauna or a hot tub
  • Soaking in a very hot bath for an extended period of time
  • Certain medications that inhibit the body’s cooling systems
  • Illness

Fever vs. Hyperthermia

A fever is different from other forms of hyperthermia. A fever is a controlled rise in temperature that is defended by a fully functional thermoregulatory system, whereas hyperthermia is a rise in core body temperature due to thermoregulation failure.

Risks Associated With Overheating

At first, overheating may not seem like that big of a deal. After all, when you aren't pregnant, you usually just need to drink more water and cool off if you feel yourself getting hot. But when you are pregnant it is not always that simple. Your temperature can rise quickly if you are not careful. And if it does, there are a number of risks to both you and your baby.

In fact, research indicates that high body temperatures during pregnancy can lead to adverse pregnancy outcomes and birth defects. Preterm birth, stillbirth, and low birth weight have all been associated with hyperthermia in pregnancy. Congenital heart defects and neural tube defects have also been linked to overheating.

In addition to overheating, research has linked a high fever during early pregnancy with neural tube defects, including spina bifida, anencephaly, and encephalocele.


When your temperature is elevated for too long, both you and your baby could be impacted. It also can cause you to become dehydrated. When that happens, it can put a strain on your kidneys, affect your cognition, gastrointestinal function, heart function, and cause headaches. For these reasons, it is important that pregnant people drink at least 8-12 glasses of water a day, and sometimes more when factoring in exercising and hot climates.

Amniotic Fluid Levels

Amniotic fluid, found in the amniotic sac, is what surrounds the baby and protects it from the external world. It also is what allows the baby to move freely and develop. And it plays a crucial role in helping to regulate the temperature so that your baby does not get too hot or too cold.

Dehydration, which is often a component of overheating, may impact the level of amniotic fluid available to the baby. Known as oligohydramnios, low amniotic fluid has been linked to birth defects, miscarriage, and even pre-term labor and stillbirth.

Pre-Term Labor

Researchers at the National Institutes of Health have found that exposure to extreme temperatures in the first seven weeks of pregnancy may increase the risk of premature birth. In particular, extreme heatwaves in early pregnancy were associated with an 11% increase in delivery before 34 weeks. In addition, exposure to extreme heat for the duration of pregnancy increased the risk of premature birth by 34 weeks by 6% and between 36-38 weeks by 21%.

Urinary Tract Infections

Overall, pregnant people are more prone to urinary tract infections (UTIs) primarily due to hormonal changes. Research associated with dehydration’s effect on UTIs is limited and older data is conflicting. However, a 2018 study on premenopausal people, who were prone to UTIs, found that increasing daily water intake protected against recurrent cystitis.

Tips for Pregnant People

You probably already know that you shouldn't sit in a hot tub or spend any time in a sauna when you are pregnant. You may even know that taking a really hot shower or bath is not a good idea. But what may surprise you is the fact that you can get overheated taking a walk on a hot day, especially if you are dressed too warmly. It's also easy to get overheated during your exercise class, especially if the gym is hot or poorly ventilated. Here are some additional tips to help you prevent overheating.

Stay Hydrated

While everyone should drink more water, for pregnant people staying hydrated is particularly important. Water not only helps keep you cool, but it also helps reduce swollen hands and ankles. Try carrying water with you wherever you go, especially if you are traveling. Do not wait until get thirsty to drink water because by then it may be too late.

Limiting caffeine can help you stay hydrated as well. Moderate caffeine consumption has been linked to smaller birth size. It is not conclusive whether reducing consumption of caffeine while pregnant to less than 200 mg may reduce these risks. Even so, avoiding or reducing your caffeine intake during pregnancy is generally considered a good idea. If you really just cannot stomach the idea of another glass of water, try adding fruit like lemon or orange to your water, or opt for a smoothie instead.

Avoid Prolonged Exercises

The U.S. Department of Health and Human Services recommends that pregnant people do 150 minutes of aerobic exercise per week. Water aerobics is a great activity to do while you are pregnant because it not only puts very little stress on your body, but it also takes place in a cool and refreshing environment.

But if water aerobics is not your thing, be sure that you exercise in a cool, well-ventilated area. For this reason, you should avoid exercise environments that are intended to be hot like "hot yoga." Remember, if you are overexerting yourself for extended periods of time or working out in extremely hot or humid conditions, chances are high that you will overheat. Doing moderate exercises in normal temperatures results in a minimal increase in core body temperatures.

Wear Loose Clothing

When choosing your maternity clothing, the key is to look for light and loose clothing. You want to wear breathable, natural fabrics such as cotton. You also should look for things that fit loosely or "flow" with your body. These types of garments allow the air to circulate. It also helps to make sure your shoes allow your feet to breathe. Even if it is winter, you want to wear comfortable shoes that allow your feet some room.

Also, keep color in mind too when choosing your clothes. Black tends to absorb sunlight and make you feel warmer when you are outside. Meanwhile, sunlight bounces off light-colored clothing.

Eat Cool Foods

Water-rich fruits and vegetables can do wonders at helping you keep cool. Some good options include melons, berries, cucumbers, oranges, and grapefruits. Even raw lettuce, celery, and carrots can help keep you cool. If you want something a little different, try popsicles made with fresh juices or a cold soup. Even a little natural yogurt with fresh fruit can be a cooling choice. And while ice cream sometimes isn't tolerated by everyone, if you are able to eat it, it can be a refreshing treat as well.

Look for Shade

If you live in or are visiting a hot climate, be sure you take precautions. Staying outside in the hot sun can be taxing on your body even if you are diligent about your water intake. As a result, try to limit the amount of time you spend in extreme summer heat. Try going outside in the mornings or in the evenings when the sun is not as hot and the temperatures are cooler. And, if your area is experiencing a heat advisory, be sure to do what you can to stay inside in a cool environment.

If you have to be outside at a family event or a work function on a hot day, look for some relief from the heat. Stay in the shade if you can. And, if the opportunity to go inside exists, take advantage of it. There is nothing wrong with sitting in an air-conditioned house or in front of a fan while you are pregnant.

If you are at a park and there are limited options for cooling off, limit your stay or take a break in the car with the air-conditioner running. You should never feel bad for taking the time to cool off. Doing so shows your wisdom and responsibility when it comes to being pregnant.

A Word From Verywell

While the risks of overheating are real, this does not mean you have to stay indoors all the time or avoid exercising. In fact, you absolutely should get outside and enjoy the fresh air. What's more, exercising during pregnancy is encouraged for most pregnant people.

As long as your doctor says it is OK, you should be able to exercise in moderation in a cool environment. Just be sure to stay cool and hydrated. And, listen to your body. If something feels off, do not push yourself. After all, you have a growing baby inside of you to consider as well.

17 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Sherri Gordon
Sherri Gordon, CLC is a published author, certified professional life coach, and bullying prevention expert.