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If You Have Asthma, Protect Yourself From Summer Heat and Smog

Summer heat is here. For some people, that may mean a rise in asthma flare-ups. Hot air, whether it’s dry or humid, may trigger asthma. But other heat-related factors may also worsen your asthma.

The U.S. Environmental Protection Agency (EPA) says ground-level ozone can harm your health. Ozone is a gas and contributes to what we typically see as smog or haze. It is the result of emissions from cars, manufacturing plants, and chemicals. It is common in the summer when there is more sunlight and low winds, especially in cities.1

These ozone levels tend to increase as the temperatures get hotter.

Often, emergency rooms see more people seeking asthma-related care in summer. This is because ozone is very irritating to the lungs and airways. It can reduce your lung function. Ozone can make it more difficult for you to breathe deeply.

The lungs of people with asthma are more sensitive to the effects of ozone, according to the EPA.2

Other groups most at risk from high ozone levels:

  • Children are at high risk of being affected by high ozone. Asthma is one of the most common chronic diseases in children. Also, kids may spend more time during the summer outdoors in camps, sports, or a park.
  • Older adults can feel the effects of high ozone pollution.
  • Active adults who work outdoors or exercise outdoors may be exposed to ozone.
  • People with certain genetics or certain nutrition deficiencies may be at greater risk of being exposed to ozone.2

How Can I Protect Myself from Summer Heat and Smog If I Have Asthma?

  • Check air quality alerts before planning outdoor activities.
  • If the alerts show ozone is high, limit your time outside. Plan outdoor activities for early morning or evening when ozone is lower.
  • Use air conditioning if you have it.

If you don’t have air conditioning:

  • See if your town or city opens “cooling centers” on very hot days. These may be schools, community centers, libraries, or other places.
  • Visit a museum, mall, or library.
  • Some libraries have free passes to museums or show free movies in the summer.

Talk With Your Doctor

Talk with your doctor about the best ways to manage your asthma during the summer heat. Make sure you keep your asthma action plan up to date. Ask your doctor if you need to adjust your plan.

And always remember when you go out, keep your quick-relief medicine with you at all times. Do not leave it behind in the car or let it sit in the hot sun.

It is important to stay up to date on news about asthma and allergies. By joining our community and following our blog, you will receive news about research and treatments. Our community also provides an opportunity to connect with other people who manage the same conditions.


1. U.S. Environmental Protection Agency. (2015, May 29). Ground-level Ozone Basics | US EPA.
2. U.S. Environmental Protection Agency. (2018, October 10). Health Effects of Ozone Pollution | US EPA.

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In addition to the heat, the humidity gets my lungs a-twitchin'. Or maybe it IS the ozone, and I just didn't have a name for it until now. I know the other night I stepped outside at nearly 11 p.m., and it was an extremely humid 78 degrees. My lungs felt as though they'd been yanked out and stomped on. 

Thank goodness for air conditioning! How did people endure before it was invented?

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