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This guide will explain how climate change impacts heat-related illness and how you can keep your child healthy in a warming climate.


Hotter temperatures are more than just uncomfortable. High temperatures can increase the chances that your child may get sick, especially if they have certain underlying medical conditions. But any child may develop heat-related illnesses.

What is heat-related illness?

Heat-related illness occurs when the body severely overheats. It’s like having a fever but there’s no infection to cause it. This can occur when a child is exposed to high temperatures for a long period of time and the body’s ability to cope with the heat wears out.

Symptoms of heat-related illness range from headaches and muscle cramps to vomiting, and, if severe enough, confusion or, if extremely severe, unconsciousness.

Some children may be more at risk for heat-related illness because they have certain medical conditions or take certain medications.

Is heat-related illness really that serious?

The most serious type of heat illness is heat stroke, which can occur if your body temperature rises to 104°F (40°C). Heat stroke can lead to damage of a child’s brain, heart, kidneys, and muscles.

Heat stroke requires emergency medical treatment because the longer you go untreated, the higher your risk for serious complications or even death.

Exposure to extreme heat may also make it more difficult for students to do well in school.

What does climate change have to do with heat-related illness?

Occasional heatwaves have always been a part of summer weather in most of the United States. However, because of climate change, the U.S. already has hotter temperatures and more frequent and intense heatwaves.

In the next few decades, if carbon pollution continues to build in the atmosphere, most of the country could see 20 to 30 more days each year with high temperatures above 90° Fahrenheit. The Southeast part of the US could be hit even harder, potentially experiencing 40 to 50 days each year with high temperatures above 90° Fahrenheit. Check out this map to see how different parts of the U.S. will experience extreme heat with or without climate action.

Which children are most at risk for heat-related illness?

Anyone can develop heat-related illness, but some children may be at higher risk than others. The following can increase your child’s risk for heat-related illness:

  • Infants and young children, especially with chronic medical conditions like asthma and diabetes. Young children need to be watched to make sure they are drinking enough water and staying hydrated.
  • Obesity. Extra weight may make it more likely for your child to develop heat-related illness.
  • Taking medications that can make it harder to cope with heat. Be aware that some medications such as diuretics, diphenhydramine (brand name Benadryl), and many medicines to treat mental health disorders, among others, may impair the ability to cope with heat.
  • Children living in urban heat islands. Urban heat islands are areas that are hotter than surrounding neighborhoods because they have little green space, more pollution from traffic, and more pavement that absorbs heat.

Due to a history of systemic oppression and racist planning policies like redlining, African Americans may be more likely to live in urban heat islands and be disproportionately exposed to extreme heat. One analysis found that by 2050, U.S. counties with large African American populations will experience about 20 more extreme heat days per year than counties with smaller African American populations.

When are children most at risk of heat-related illness?

Sometimes children develop heat-related illness because they are left alone in a car (called “vehicular heat stroke”) or they are living in a place that doesn’t have air conditioning. Over the past 20 years, an average of 37 children died each year of vehicular heat stroke in the US. Most of the children who died (87%) were younger than 3 years old.

Athletes are also at risk of heat strokes, which can occur after long, strenuous exercise. About 9,000 high school athletes are treated for exertional heat illness each year, with football players at highest risk.

How can I protect my child from heat-related illness?

Here are some ways to protect your child from extreme heat from the CDC:

  • Never leave a child alone in a parked car
  • Make sure your child drinks plenty of fluids (like water or low-sugar sports drinks)
  • Dress young children in loose, lightweight, light-colored clothing to help them stay cool
  • If you think your child may have a heat-related illness, call their doctor right away
  • If your child plays sports, make sure there are emergency protocols in place to treat heat stroke. The Centers for Disease Control and Prevention have additional resources about protecting athletes from heat.

How can I do my part to take action against climate change and prevent more high heat days?

Climate change can feel scary and overwhelming, but the good news is we already have solutions to slow down climate change and improve the health of your child and children all over the world.

Here are a few simple steps you can take:

  • Plant trees and other vegetation where you live, and encourage your community to do the same. Trees provide shade to help you stay cool on hot days. Adding trees and other vegetation to your neighborhood can also help improve the air quality where you live, especially in urban areas, and can improve mental health.
  • Choose walking, biking or public transit whenever possible, and consider carpooling. If you are buying a car, choose an electric car or find one with better fuel economy. The more gas a car burns per mile, the more harmful air pollution it generates. Getting exercise may also help improve a child’s mental health.
  • Reduce, reuse, and recycle. A timeless piece of advice. The more we buy new, the greater our carbon footprint.
  • Invest in energy efficiency and renewables. Ask your local leaders to invest in renewable energy in public buildings, and support building regulations that require solar panels and energy-saving policies for new buildings. Conserving energy saves money and reduces our carbon footprint.
  • Start a conversation. Talk to your family and friends about climate change to make sure they know it’s a health issue, especially for our children, and that we need to work with everyone to take action to fight this climate crisis. Work with your place of worship and in your children’s school to see what you can do to spread the word and keep our kids healthy, and get involved in climate change planning at the state and local level.
  • Get involved. Many towns and cities want to decarbonize—in fact they’re leading on this issue—and parents can play a role in shaping those efforts. Ask local leaders how your neighborhood can become safer and healthier by making it greener, more walkable and bike-friendly. You can ask decisionmakers to add green space by planting trees, increase access to public transit and invest in electric vehicle infrastructure. These actions will benefit everyone’s health and especially the health of our children.

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The contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. Harvard Chan C-CHANGE does not recommend or endorse any products.

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Dr. Aaron Bernstein

Aaron Bernstein MD, MPH

Aaron examines the human health effects of global environmental changes with the aim of promoting a deeper understanding of these subjects among students, educators, policy makers, and the public.

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