Emergency Preparedness and Response: Extreme Heat

Prepare and Act

It’s both important to prepare for extreme heat and remain safe during hot weather. This section provides information on what to do before and during extreme heat events.

Before Extreme Heat Events

Preparation is crucial to ensuring safety in the event of extreme heat. This section includes some steps you can take before extreme heat begins.

Healthy Homes Maintenance Checklist for Thermal Control: Extreme Heat NEW 
This checklist provides a list of activities you can complete in your home to prepare for the possibility of experiencing extremely hot temperatures. [pdf; NCHH, 2022]

Be Prepared for Extreme Heat
Ready.gov lists some simple steps you can take before extreme heat. [pdf; Ready.gov]

  • Prepare window reflectors, such as aluminum foil-covered cardboard, to reflect heat back outside.
  • Weather-strip doors and windows.
  • If you have window air conditioners or are installing them, make sure the air around them is sealed or insulated.

Heat Wave Safety
The Red Cross emphasizes some things you can do before a heat wave. [url; Red Cross]

  • Gather food, water, and medicine in advance. Organize your supplies into a “go-kit” (three days of supplies that you can carry with you) and a “stay-at-home kit” (two weeks of supplies if you need to stay at home).
  • Make a plan to go to a cool place if you do not have air conditioning. This might include identifying a friend or neighbor who has air conditioning, checking to see if local shopping malls or libraries are open, and identifying local cooling centers. For more information about cooling centers, read the section further down on this page or visit our Cooling Centers by State page.

This resource also includes information on the three types of alerts you are likely to see from weather forecasters prior to and during a heat event:

  1. Excessive Heat Outlook means that the potential exists for an excessive heat event in the next 3-7 days.
  2. Excessive Heat Watch is an alert that means conditions are favorable for an excessive heat event in the next 24-72 hours.
  3. Excessive Heat Warning/Advisory is an alert issued within 12 hours of the beginning of an extreme heat event.

Climate Change and Extreme Heat: What You Can Do to Prepare
This resource from the Centers for Disease Control and Prevention (CDC) provides an overview of extreme heat, why extreme heat events are increasing, and the connection to health. Page 16 includes tips to prepare for extreme heat events, including the following:

  • Check your fans, thermostat, air conditioning, and cooling equipment to ensure they work.
  • Make a list of family, friends, and neighbors who might need assistance and make sure you have their phone numbers.
  • Subscribe to local heat alert systems.

The document also includes advice about how you can get involved in preparing for extreme heat events in your workplace, your children’s schools and athletic organizations, and community. [pdf; CDC, 2016]

During Extreme Heat 
The CDC summarizes their tips for preventing heat-related illness into three points: staying cool, staying hydrated, and staying informed. Also available en español. [url; CDC, 2017]

Energy, Weatherization, and Funding Resources

There are often resources available to help low-income consumers and families weatherize homes and pay for increased energy costs:

  • The LIHEAP program will provide assistance with energy bills, allowing families to stay warm in the winter and cool in the summer.
  • Local weatherization programs provide free services to improve homes and make them more energy efficient. This may include repair or installing air conditioning units. Utilities may also provide these services.

These resources may be helpful to anyone struggling with energy needs, not just those affected by extreme heat. For more information on this and other resources, see our Policy Levers and Actions page.

Staying Cool

This section provides further resources on ways to preventing heat-related illness and what to do during the day.

  • Stay indoors and use air conditioning to keep cool.
  • Access cooling shelters if air conditioning is not available.
    • Locate cooling centers or contact your local health department.
    • Cooling centers are air-conditioned spaces that local governments may set up to provide shelter during extreme heat events.
    • Cooling centers might provide visitors with amenities and services to reduce the risk of heat-related illnesses. Other air-conditioned public spaces such as public libraries, community centers, and malls can also serve as cooling centers.
    • Visit our page on Cooling Centers by State to learn how to locate cooling centers in your area.

What You Can Do in Your Home

There are several things you can do to keep your home cool during extreme heat in addition to running your air conditioning or if you don’t have air conditioning in your home.

Increase Air Movement

Stagnant or stuffy air contributes to heat and also can worsen indoor air quality by allowing pollutants to build up in a room. Here are two ways to combat heat:

  • Create a wind chill effect by blowing air on skin to cool down. Note that when the temperature is in the high 90s, this will not prevent heat-related illness.
  • Help to ventilate a room. If the outdoor air is cooler than the indoor air, you can use fans to blow hot air out of the home. This can be true particularly at night when temperatures are cooler.

Ventilation plays an important role in keeping our indoor air safe and addressing pollutants and hazards. If your area is experiencing poor air quality in conjunction with high heat (such as from a wildfire event) it’s important to know how to protect your indoor air as well as lower the temperature, especially if you don’t have air conditioning. For more information on ventilation and filtration, visit the following NCHH resources:

You can also use fans to create air movement. There are a few types of fans that can be helpful:

  • Ceiling fans should be set to rotate counter-clockwise during the summer. This pushes air downward and creates air movement that cools the body. (If you’re trying to create air movement in the winter without cooling the room down and feeling the draft, you can run a ceiling fan clockwise.)
  • Box fans can be a less expensive option and offer the additional benefit of portability.

In addition, humid air feels warmer than dry air. If your area is experiencing humid heat, and you don’t have air conditioning, using a dehumidifier can help. In dry climates, evaporative (swamp) coolers are used for the opposite effect, to add moisture to the air.

Reduce Radiant Temperatures

Lessen the amount of heat that enters your home from outside and the amount of heat created from within.

  • Block sunlight by covering windows during the day.
  • Avoid using appliances that generate heat. This includes ovens and stoves.
  • Keep the refrigerator doors closed. Rather than introducing cool air into the room, leaving your refrigerator door open will make your house hotter as the refrigerator works to create more cool air.

Staying Hydrated

Hydrate with water and limit energy drink and alcohol consumption. You should also provide plenty of water for pets and leave the water in a shady area.

Heat Stress: Hydration
[pdf; CDC/NIOSH, 2017]

Staying Informed

Keep updated with local information on extreme heat events by using the CDC’s Heat and Health Tracker application and the National Integrated Heat Health Information System website.

Heat and Health Tracker
This map provides up-to-date information on how extreme heat events are directly impacting the health of communities through tracking temperatures and heat-illness-related emergency room visits. [CDC]

National Integrated Heat Health Information System
Developed by the Centers for Disease Control and Prevention (CDC) and the National Oceanic and Atmospheric Administration (NOAA), the National Integrated Heat Health Information System (NIHHIS) website provides temperature and heat index probabilities for up to the next 14 days. The website also has information on health risks, safety tips, and a place to view heat warnings by state. [url; NIHHIS]

Check in with family members, neighbors, and those who might be socially isolated.

Watch for symptoms of different heat-related illnesses

National Weather Service Heat Infographics: Heat Exhaustion vs. Heat Stroke
Knowing the difference between heat illnesses can be a matter of life or death. This National Weather Service (NWS) infographic explains some of the common differences in symptoms between heat exhaustion and heat stroke. While both are heat-induced, heat stroke is potentially deadly. [url/jpg; NWS Sacramento]

Warning Signs and Symptoms of Heat-Related Illness
This CDC infographic provides more information on other heat-related illnesses and what to do in each case. Also available en español. [url/pdf; CDC, 2017]

First Aid

Long-term exposure to extreme heat can cause various heat-related illnesses that have different levels of severity. It’s important to identify signs of these heat illnesses and act quickly.

Heat Stress: First Aid for Heat Illness
[pdf; CDC/NIOSH, 2017]

Heat Related Illness (HRI) Prevention: Recognizing, Preventing, and Treating Heat-Related Illness (WB233)
This free training available from CDC teaches about heat-related illness symptoms and their treatments. [url; CDC]