Department of Emergency Management and Security

CONTACT INFORMATION: Open during regular business hours 8 a.m. - 4:30p.m., Monday - Friday
4890 Alliance Drive, Suite 2200, Fairfax, VA 22030
Seamus Mooney

Extreme Heat

What It Is

Extreme heat - especially coupled with high humidity - can be deadly, slowing evaporation and thus requiring the body to work harder to moderate its core temperature. Overexposure to hear and/or overexertion (too much exercise or effort) can trigger a heat-related illness: heat cramps, heat exhaustion, and eventually heat stroke. Heat-related illness is a particularly high risk for children, older adults, and those who are infirm or overweight.

Extreme Heat Hazard Annex


Extreme Heat Hazard Annex

Click on the appropriate link below to download a PDF copy of the Extreme Heat Hazard Annex page from the Community Emergency Response Guide.

English (PDF) | Spanish (PDF) | Korean (PDF) | Arabic (PDF) | Mandarin (PDF) | Vietnamese (PDF)

Key Terms

  • Heat Wave is a prolonged period of excessive heat, often combined with high humidity.
  • The Heat Index indicates how hot it feels, with relative humidity and sun exposure added to the absolute air temperature.  Exposure to full sunshine can increase the heat index by 15 degrees.
  • Heat Cramps are muscular pains and spasms due to heavy exertion.
  • Heat Exhaustion typically occurs when people exercise heavily or work in a hot, humid place, and body fluids are lost through heavy sweating.  Heat exhaustion must be treated with fluids and cooling of the skin, or it will turn into heat stroke.
  • Heat Stroke (or "sun stroke") is a life-threatening condition in which the victim's temperature-control system, which produces sweat to cool the body, stops working.  Heat stroke victims will be completely incoherent or unconscious, and they require immediate medical attention.

What To Do

  • Sign up for Fairfax Alerts and have a battery or crank powered NOAA weather radio available.
  • If you have an air conditioner, have it serviced regularly.
  • Drink plenty of fluids. Know your body and know what is normal.
  • Dress in loose-fitting clothes that cover as much skin as possible. Lightweight, light-colored clothing reflects heat and sunlight and helps maintain normal body temperatures.
  • Reschedule outdoor activities, if possible.
  • Never leave children or pets alone in closed vehicles.
  • Learn First Aid.
  • Refer to “Power Outage/ Blackout” and “Medical Emergency" hazard pages.

  • Stay indoors as much as possible and limit exposure to heat and sun.
  • Drink plenty of water or electrolyte sports drinks.
  • Avoid strenuous work during the warmest part of the day.
  • Use a buddy system when working in extreme heat, have a phone handy, and take frequent breaks.
  • If you must exercise, consider indoor activities. If you must exercise outside, do so during cooler parts of the day, drink extra fluids, use a buddy system, have a phone handy, and reduce your level of effort.
  • If you feel woozy, overheated, or unwell, take action immediately!
    • Stop any strenuous activity.
    • Get somewhere cool.
    • Drink something if you can.
    • Cool your skin by taking a cold bath or holding anything cold against your body.
    • Call someone for help, or call 911 - do this before your condition compromises your critical thinking skills.
  • Check on older neighbors and any neighbors without air conditioning.

  • Consult a medical professional if a heat-related condition does not approve.
  • Continue to hydrate.
Fairfax Virtual Assistant