Ready.gov · FEMA

Extreme Heat

Recognizing heat illness and the cooling measures that reverse it.

Source: FEMA. Not endorsed by FEMA or the U.S. Government.
Last checked against the source 2 October 2026

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How to use this document

Who it's for: anyone facing a heat wave, especially older adults, children and outdoor workers, and the people looking after them.

How to read it: Before and During Extreme Heat cover preparation and staying cool. Heat-Related Illnesses is the part to know by heart: how to recognize each one and what to do.

Read alongside: About Heat and Your Health · How Long Can You Survive Without Water?

Read with careFEMA last updated this page on 16 July 2026; we copied it on 30 September 2026. FEMA revises this guidance, so check the original for the current version, and in a real emergency follow instructions from local officials.

The full text

Extreme heat is a period of high heat and humidity with temperatures above 90 degrees for at least two to three days. In extreme heat your body works extra hard to maintain a normal temperature, which can lead to death. Extreme heat is responsible for the highest number of annual deaths among all weather-related hazards.

Older adults, children and people with certain illnesses and chronic conditions are at greater risk from extreme heat.

Humidity increases the feeling of heat.

Before Extreme Heat

  • Learn to recognize the signs of heat illnesses.
  • Do not rely on a fan as your primary cooling device. Fans create air flow and a false sense of comfort, but do not reduce body temperature or prevent heat-related illnesses.
  • Identify places in your community where you can go to get cool such as libraries and shopping malls or contact your local health department to find cooling options in your area.
  • Cover windows with drapes or shades.
  • Weather-strip doors and windows.
  • Use window reflectors specifically designed to reflect heat back outside.
  • Add insulation to keep the heat out.
  • Use a powered attic ventilator or attic fan to regulate the attic temperature by removing hot air.
  • Install window air conditioners and insulate around them.
  • If you are unable to afford your cooling costs, weatherization or energy-related home repairs, contact the Low Income Home Energy Assistance Program (LIHEAP) for help.

During Extreme Heat

  • Never leave people or pets in a closed car on a warm day.
  • If air conditioning is not available in your home find a cooling center.
  • Take cool showers or baths.
  • Wear loose, lightweight, light-colored clothing.
  • Use your oven less to help reduce the temperature in your home.
  • If you’re outside, find shade. Wear a hat wide enough to protect your face.
  • Drink plenty of fluids to stay hydrated.
  • Avoid high-energy activities or outdoor work during midday heat if possible.
  • Check on family members, older adults and neighbors.
  • Watch for heat cramps, heat exhaustion and heat stroke.
  • Consider pet safety. If your pets are outside make sure they have plenty of cool water and access to comfortable shade. Asphalt and dark pavement can be very hot to your pet’s feet.
  • Heat waves may cause you to lose power. Visit Power Outages to learn how to stay safe.

Heat-Related Illnesses

Know the signs of heat-related illnesses and ways to respond. If you are sick and need medical attention, contact your healthcare provider for advice and shelter in place if you can. If you are experiencing a medical emergency call 9-1-1.

Get more detailed information about heat-related illnesses from the CDC and National Weather Service.

HEAT STROKE

  • Signs: Extremely high body temperature (above 103 degrees F) Red, hot and dry skin with no sweat Rapid, strong pulse Dizziness, confusion or unconsciousness

If you suspect heat stroke, call 9-1-1 or take the person to a hospital immediately. If possible, move the person suffering from heat stroke into a cool, shaded area. Remove any outer clothing. Place a cold, wet cloth or ice pack on the head, neck, armpits, and groin. Alternatively, soak the person’s clothing with cool water. Elevate their feet.

HEAT CRAMPS

  • Signs:Muscle pains or spasms in the stomach, arms or legs

HEAT EXHAUSTION

  • Signs:Heavy sweating, paleness, muscle cramps, tiredness, weakness, fast or weak pulse, dizziness, headache, fainting, nausea, vomiting

If you have signs of heat cramps or heat exhaustion,go to a cooler location and cool down by removing excess clothing and taking sips of sports drinks or water. Call your healthcare provider if symptoms get worse or last more than an hour.

Summer Break

While the kids are home for the summer, get the whole family prepared.

  • Make a family communication plan and include the whole family.
  • Practice evacuation plans and other emergency procedures with children on a regular basis.
  • Teach kids when and how to call important phone numbers like 9-1-1.
  • Make sure the kids have an emergency contact person and know how to reach them.
  • Create a family password or phrase to prevent your child from going with a stranger.
  • Keep the kids occupied with online emergency preparedness games.
  • Download the free Prepare with Pedro activity book to help kids learn to prepare.
  • Decide on a family meeting place you can go if separated.

Take it with you

Free, no sign-up. The PDF, phone PDF, EPUB and text copies are made by Survival Codex from the agency's own page, with a cover and closing page from us; the agency's text is unchanged. EPUB opens in Apple Books and on Kobo, and on Kindle through Send to Kindle.

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