Extreme Heat

Generally, extreme heat is defined as temperatures that hover 10 degrees or more above the average high temperature for the region that last for prolonged periods of time and are accompanied by high humidity that the body cannot tolerate.

See how to determine your risk, prepare your family, learn about your building code, and identify ways to strengthen your home against extreme heat.

Make a plan for what to do before, during, and after the next heat wave


Prepare for extreme heat by building a disaster supply kit, and prioritizing drinking water for people and pets. Keep cool air from escaping your home by weatherizing your home’s windows and doors each year. Maintain air conditioning systems.

Plan for a power outage, and consider purchasing a portable or whole-home generator.


When temperatures rise, stay indoors and monitor the weather, following the advice of local authorities. Wear loose, lightweight, light-colored clothing and drink plenty of fluids to stay hydrated.

If air conditioning is not available in your home, go to a cooling center in your community. In the event of a power outage, use generators safely.


After a period of extreme heat, check on family members, seniors, and neighbors. Know the signs of heat-related illness, and understand treatment options.

Inspect your home for damage caused by excessive moisture and humidity. Make all necessary repairs to reduce your health and safety risk during future events.

Get customized recommendations to protect your home.

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Top Extreme Heat-Resilient Home Retrofits and Upgrades

Cover Your Windows to Keep Cool in Extreme Heat
Cover Your Windows to Keep Cool in Extreme Heat
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Install an Attic Ventilator Fan
Install an Attic Ventilator Fan
Learn More
Prepare Windows and Doors
Prepare Windows and Doors
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Prepare for Power Outage in Extreme Heat: Purchase a Generator
Purchase a Generator
Learn More
Upgrade Wall Insulation
Upgrade Wall Insulation
Learn More

Free or Low-Cost Things You Can Do Right Now to Prepare for Extreme Heat

Build a Disaster Supply Kit
Build a Disaster Supply Kit
Learn More
Plan for a Power Outage and Use Generators Safely
Plan for a Power Outage and Use Generators Safely
Learn More
Watch vs. Warning Extreme Heat

An Excessive Heat Watch is issued when there is a potential for the heat index value to reach or exceed 110 degrees (east of the Blue Ridge) or 105 degrees (west of the Blue Ridge) within the next 24 to 48 hours.

Watch vs. Warning Extreme Heat

An Excessive Heat Warning is issued when the heat index value is expected to reach or exceed 110 degrees (east of the Blue Ridge) or 105 degrees (west of the Blue Ridge) within the next 12 to 24 hours. An Excessive Heat Warning may be issued for lower criteria if it is early in the season or during a multi-day heat wave.

We’re here to help you before, during, and after a disaster

The Federal Alliance for Safe Homes (FLASH) — a 501(c)(3) nonprofit organization — is the leading consumer advocate for strengthening homes and safeguarding families from natural and manmade disasters.

Buyer’s Guide to Resilient Homes

This guide helps homeowners and homebuyers understand their resilience options.

National Disaster Resilience Conference

This annual conference brings together the nation’s leading voices in disaster safety.

No Code No Confidence – Inspect2Protect

Inspect2Protect will help you understand the building code where you live.

Learn About Heat Waves

What is heat stroke?

Heat stroke is a severe and life-threatening condition that can occur when the body’s temperature regulation system fails, and body temperature rises to a dangerous level. It is the most severe form of heat-related illness.

During heat stroke, the body cannot regulate its temperature through sweating, leading to a rapid rise in body temperature. This can cause damage to internal organs, particularly the brain, leading to severe complications or even death if left untreated.

Symptoms of heat stroke may include:

  • High body temperature (above 103°F/39.4°C)
  • Hot, dry skin or sweating
  • Rapid pulse
  • Headache
  • Dizziness
  • Confusion or disorientation
  • Nausea and vomiting
  • Seizures
  • Loss of consciousness

Call 911 immediately if you suspect someone is experiencing heat stroke. Take steps to lower the person’s body temperature. This may include moving them to a cool, shaded area, removing excess clothing, and applying cool water or ice packs to the skin.

Hospital-based treatment may include intravenous fluids, medications to lower body temperature, and monitoring for complications such as organ damage.

Early recognition and treatment of heat stroke are crucial to prevent serious complications or death.

Who is at greatest risk for heat-related illness?

  1. Older adults are at risk because our bodies become less efficient at regulating body temperature, and our sweat glands become less responsive as we age. This makes it harder for elderly individuals to cool down during hot weather, putting them at greater risk for heat exhaustion and heat stroke.
  2. Young children are also at increased risk because their bodies are less able to regulate temperature than adults. They may also be less likely to recognize or communicate their symptoms of heat exhaustion or heat stroke.
  3. People with chronic medical conditions like heart disease, diabetes, and obesity may have difficulty regulating body temperature during hot weather. Certain medications can also affect the body’s ability to regulate temperature, putting individuals at greater risk for heat-related illness.
  4. People who work outdoors, particularly in direct sunlight, are at greater risk for heat exhaustion and heat stroke. This includes construction workers, landscapers, and agricultural workers.
  5. Athletes participating in outdoor sports or people attending events during hot weather are at increased risk for heat-related illness, making adequate breaks and hydration essential.