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Extreme Heat

ALWAYS CALL 911 if you are in immediate danger and need emergency help.

Individuals, communities, and businesses can plan for and reduce the effects of extreme heat. Keep yourself and your family cool when the thermometer tops out. Check weather alerts and warnings from the National Weather Service.

Prepare for extreme heat

! EPA Warning: Recharging air conditioners with the wrong refrigerant poses injury and fire risks. Do not recharge or use a propane-based refrigerant such as "22a" in any air conditioner that is not designed to use propane or flammable refrigerants.

Homeowners - check home cooling systems before you need them:

Starting in springtime to be sure that ways you cool your home are checked and ready for the coming hot weather. 
  • Clean and trim around outdoor HVAC units so air can flow freely. Wash dust and dirt from cooling coils.
  • Have a contractor do annual, pre-season check-ups.
  • Use fans? Check that ceiling or tabletop fans are in good working order. Clean fan blades so the motor can work efficiently and move air better.
  • Read more: maintenance checklist for your cooling system, from EnergyStar.

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Communities and facilities - adopt development strategies to reduce heat islands and coordinate local efforts:

Urban and suburban areas can be "heat islands," a zone 2-10 degrees F warmer than the surrounding rural countryside. Because they are warmer, heat islands use more energy to keep cool, which raises costs and reduces air quality. Communities can invest in long-term strategies such as:
  • Promoting or installing cool or vegetated "green" roofs
  • Planting more trees and vegetation
  • Switching to cooler paving materials.
Cities are increasingly starting heat wave response programs that coordinate efforts among local agencies and alert residents. Common examples of "best practices" include:
Building owners can follow five steps to save energy in summer:
  • Measure the energy use of your building(s) and set an energy savings goal.
  • Inspect cooling system equipment now and perform monthly maintenance.
  • Turn back, or turn off cooling equipment when not needed.
  • Get the occupants involved.
  • Improve lighting systems.
  • More ideas from

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During extreme heat

Today's AQI forecast USA map. Click for summary info.

Check air quality where you live - hot weather can worsen ozone levels and other types of air quality.

CALL 911 in case of heat-related illness - heat stress, heat exhaustion or HEAT STROKE can result in death.

ALERT: Generator exhaust is toxic. If you lose power, ALWAYS put generators outside well away from doors, windows, and vents. Never use a generator inside homes, garages, crawlspaces, sheds, or similar areas. Carbon monoxide (CO) is deadly, can build up quickly, and linger for hours. More information.

PREVENTION IS THE BEST DEFENSE! Stay out of direct sun and wear sunscreen of SPF 15 or higher. Be extra careful about sensitive individuals like children, the elderly, or the sick. Never ever leave anyone or an animal alone in a car, or a pool or other risky location, not even for "just a few minutes."

Limit your outdoor activity to morning and evening. Spend time in cool places like a shopping mall, a library, or a theater.

Remember pets! Make sure all animals have plenty of fresh water and are able to move out of direct sunlight.


  • Save energy - reduce your home power use to help reduce brownouts or blackouts and smog/air pollution. Turn off nonessential lights, televisions, games, and computers, and unplug chargers.
  • Overexposure to the sun's ultraviolet (UV) radiation can result in a painful sunburn. It can also lead to more serious health problems, including skin cancer, premature aging of the skin, and other heatlh problems. Children are particularly at risk.
  • Learn more about Sun safety action steps.


Drive smarter! Find ways to help save fuel and reduce emissions if you're driving in hot weather.
  • Roll the windows down at lower speeds; use the AC at highway speeds. Overcoming the air drag from open car windows at highways speed uses more fuel than the air conditioner.
  • Drive with the windows open for a short time before using the AC, to let out the hot air before you run the AC.
  • Park in the shade or use a sunshade or pop-up window screens.
  • More about fuel economy in hot weather.

Don't top off! When you fill up remember not to top off your gas tank. Topping off can spill gasoline which quickly evaporates into the air around you. Gasoline vapors can harm your family's health and make ozone pollution and smog worse. And in hot weather, buy gas when it's cooler in the early morning or after sundown. 

Extreme heat can make drought worse. More about drought.

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