Protect Yourself from Heat and Smoke

Wildfire smoke and heat events are becoming more frequent and are lasting longer. Smoke and heat can both be dangerous. Scientific evidence suggests that exposure to smoke and heat at the same time may be much worse for your health than exposure to either of them alone. This fact sheet includes information about actions you can take to protect yourself and your family.

On this page:

What Can Happen?
Who Is at Risk?
What Can I Do?
Resources

What Can Happen?

Wildfire smoke: The fine particles (also called PM_2.5 or fine particle pollution) in smoke can affect the lungs, heart, and other organs, and can lead to asthma attacks and make chronic obstructive pulmonary disease (COPD) worse. It can also increase the risk of heart attacks, heart failure, and death. See the At-Risk Groups of People Wildfire Guide fact sheet for more information.

Heat: If temperatures are hotter than usual, your body may not be able to cool itself fast enough. This can lead to heat-related symptoms and illnesses, such as heat rash, muscle cramps, heat exhaustion, heat stroke, and death. High humidity and high nighttime temperatures, alcohol use, prescription drug use, and sunburn might increase your risk of developing a heat-related illness. See the Centers for Disease Control and Prevention’s (CDC) websites About Heat and Your Health and People at Increased Risk for Heat-Related Illness for more information.

Who Is at Risk?

If you are at increased risk from the health effects of wildfire smoke, you are also likely at increased risk from heat. This includes people with heart or lung disease, older adults, children and teenagers, and pregnant women. People who spend more time exposed to wildfire smoke and heat (such as outdoor workers and people experiencing homelessness), people who can’t reduce their exposure to smoke or heat indoors, and people exercising outdoors are also at increased risk. Exposure to wildfire smoke and heat at the same time may increase your risk of health effects.

What Can I Do?

Take the following steps to help protect yourself from wildfire smoke and heat.

1) Plan:

If you are at increased risk from either smoke or heat, check with your health care provider about what to do during smoke and heat events.

Know where to find your local Air Quality Index (AQI) on the Fire and Smoke Map and wildfire smoke advisories from your state, Tribal, or local government.

Keep an eye on weather forecasts and heat advisory information. The CDC’s HeatRisk dashboard provides a seven-day national-scale heat forecast that tells you when temperatures could reach levels that could harm health and what to do about them.

Check with your state, Tribal, or local government to find out whether there are cleaner air and cooling centers available in your community during episodes of wildfire smoke or heat. You can also try calling 2-1-1 for referrals to local cooling centers or see the National Center for Healthy Housing Cooling Centers by State website for more information.

2) Know the symptoms of exposure to smoke and heat:

Smoke can cause a range of health effects—including less serious effects, such as eye, nose, or throat irritation, coughing, or wheezing—that resolve when the air clears. If you experience these health effects, go somewhere with cleaner indoor air, or wear a well-fitting particulate respirator such as an N95^© respirator, also known as an N95 mask, when outdoors. See the Protect Your Lungs From Wildfire Smoke and Ash Wildfire Guide fact sheet.

Smoke may also cause severe problems, such as worsening of heart and lung diseases. If these occur, seek medical attention. See EPA’s Wildfire Smoke and Health Wildfire Guide fact sheet and CDC’s Safety Guidelines: Wildfires and Wildfire Smoke for more information. Healthy people are likely to have only symptomatic effects from short-term (hours to days) exposure to smoke.

Never ignore the symptoms of heat-related illness. Early symptoms include feeling unwell, headache, sweating and thirst, nausea, lightheadedness, fatigue, heat rash, or muscle cramps. If you have these symptoms, go somewhere cool and sip water until symptoms improve. Seek medical attention if your symptoms do not improve.

You need immediate medical attention if you have more serious symptoms, including fainting or loss of consciousness, weakness, extreme fatigue, severe nausea, and difficulty speaking. See CDC’s About Heat and Your Health for more information.

3) Reduce your exposure to smoke and heat:

Be aware of current smoke and heat conditions by checking the AQI on the Fire and Smoke Map and heat information from the National Weather Service.

Follow these tips when you are outdoors:

Limit strenuous activity and exercise. Pay attention for early signs of heat-related illness.
Stay hydrated (choose water or drinks with electrolytes over sugary beverages).
Consider using a NIOSH Approved® N95® respirator to reduce smoke exposure.
Remove the respirator if it becomes uncomfortably warm or leads to symptoms of
heat-related illness.
Keep an eye on air quality and temperature conditions and time your outdoor activities for less smoky and cooler times of day.
Be aware that sometimes the coolest part of the day can also be the smokiest part of the day. Consider using an N95® respirator if the cooler part of the day is a smokier time.
Rest often in shady areas.
Wear lightweight, loose-fitting clothing (absorbent or wicking clothing is also appropriate).
Over the course of a work shift, outdoor workers may face greater or more prolonged exposure to both smoke and heat and have less ability to spend time indoors than the general public. Because of this, outdoor workers should be especially careful when there is both smoke and heat present and take what measures they can to reduce exposure to both.

Follow these tips when you are indoors:

During heat, you must cool down your home, and you may need to allow smoke inside while using night air for cooling. Both smoke and heat are harmful to your health, but for most people, heat is more immediately dangerous.

If You Do Not Have Air Conditioning

To help control indoor temperatures:

During the day when it is hot outside, close windows and window coverings, such as shades, blinds, and awnings.
At night when it is cooler, open the windows and use fans to exhaust hot air from rooms or draw in cooler air. Do not direct the flow of fans toward yourself when the room is hotter than 90°F to avoid dehydration.
Once the air indoors is cool, close doors and windows.
Use a portable air cleaner or a DIY portable air cleaner (i.e., box fan with a high-efficiency filter) to filter the indoor air. If you have forced air heat, you can also set the furnace fan to “on” at the thermostat (with heat off) and use a high-efficiency furnace filter (MERV 13 or greater).

If you cannot tolerate smoke and cannot stay cool, go somewhere to cool off during the smoke event.

If your community has designated a cleaner air and cooling center, spend time there to get relief from both the heat and smoke.
Otherwise, spend time in public places with cooler indoor air, such as libraries, community centers, and shopping malls.
Consider staying with family and friends who have air conditioning and air cleaners or high-efficiency HVAC filters in use, especially for extended heat events where the temperature stays elevated at night or when humidity is high.

If You Have Air Conditioning

Central air conditioning:

Ensure your system is functioning properly and install the highest-efficiency filters your system can use to filter the PM_2.5 in smoke. MERV 13 or higher filters are best, if they are compatible with your HVAC system.
During a smoke event, run your system’s fan all the time. Otherwise, your air will only be cleaned while cooling.
Use portable air cleaners or DIY portable air cleaners to filter your indoor air, especially if your system cannot use high-efficiency filters.
If your system has a fresh air intake, close it or turn the system to “recirculate.”

Window air conditioner, portable air conditioner, mini split heat exchanger:

These devices typically do not have filters designed for the PM_2.5in smoke. Use portable air cleaners or DIY portable air cleaners to filter your indoor air.
Make sure the seal between the air conditioner and the window or wall is as tight as possible to keep smoke out.
Use portable air conditioners with a single hose sparingly during smoky conditions—these can bring more smoke inside.
Create a clean room in the room served by the air conditioner. Learn more about How to Create a Cleaner Air Room at Home.

Evaporative (swamp) cooler:

If safely accessible, completely cover the outside air intakes with 4-inch-thick high-efficiency (MERV 13) furnace filters. Note: The external filters will be vulnerable to damage from wind or rain and may need to be replaced frequently.
If you cannot cover the outdoor air intakes with high-efficiency filters, use the evaporative cooler sparingly during smoky conditions.
In high humidity, evaporative coolers cannot cool the air well. Follow the steps under “If You Do Not Have Air Conditioning” if you cannot cool your home.

Resources

Information on Air Quality

Check out the AirNow Fire and Smoke Map, your state air quality website, or your local news for air quality information. Access these resources using the links below.