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Extreme Heat

Each summer, residents and tourists enjoy the warm weather and sunny beaches, but many may be unaware of just how hot it can get in in Jacksonville. Extreme heat is dangerous because it can push your body temperature beyond its limits. If your body can’t cool itself fast enough, permanent damage or even death can occur. When there's a heat risk in Jacksonville, the National Weather Service will issue alerts and warnings. 

Heat Safety Information

Heat Alerts and Warnings
Monitoring for Heat Advisory or Excessive Heat Conditions
The potential for Heat Advisory or Excessive Heat conditions will be highlighted in the NWS Jacksonville Daily Briefing and via official NWS Jacksonville forecasts.
Excessive Advisory
A Heat Advisory is typically issued within 12 hours of forecast heat index values in the 108-112°.
Excessive Heat Advisory
A Heat Advisory is issued within 12 hours of the onset of extremely dangerous heat conditions, when the maximum heat index temperature is expected to be 100° or higher for at least 2 days, and night time air temperatures will not drop below 75°.
Excessive Heat Warning
An Excessive Heat Warning is typically issued within 12 hours of the onset of extremely dangerous heat conditions when the maximum heat index is expected to be 113°F or higher for at least 2 hours.
During Extreme Heat
Stay Cool
  • Stay inside in an air-conditioned area during peak heat hours. 
  • Avoid unnecessary exertion.
  • Wear light, loose fitting clothing.
  • Stay out of the sun and wear a hat. Take breaks often.
  • Check on family, friends, and neighbors.
  • Don't leave your pets outside or in a car.
Stay Hydrated
  • Drink plenty of water, even if you don’t feel thirsty.
  • Avoid alcohol and sugary drinks.
  • Remind others to drink water.
Stay Informed
  • Stay informed about current weather conditions.
  • Know the symptoms of heat illness. 

Heat Related Illnesses
Children under 4, adults over 65, and people who are overweight or ill are especially at risk of heat-related illnesses. Here’s how you can recognize heat-related illness and what you should do. 

Heat Exhaustion


  • Heavy sweating
  • Weakness
  • Cold, pale, and clammy skin
  • Weak pulse
  • Fainting and vomiting


What You Should Do

  • Move to a cooler location
  • Lie down and loosen your clothing
  • Apply cool, wet cloths to as much of your body as possible
  • Sip water
  • If you have vomited and it continues, seek medical attention immediately


Heat Stroke


  • High body temperature (above 103°F)
  • Hot, red, dry, or moist skin
  • Rapid and strong pulse
  • Possible unconsciousness


What You Should Do

  • Call 911 immediately — this is a medical emergency
  • Move the person to a cooler environment
  • Reduce the person's body temperature with cool cloths or even a bath
  • Do NOT give fluids
Places To Stay Cool

Use the map below to locate places where you can stay cool and out of the heat during the summer months in Duval County. 

Keep Your Pets Safe in Extreme Heat
  • Avoid dehydration: Pets can dehydrate quickly, so give them plenty of fresh, clean water.
  • Don't leave your pet in a parked car: ON A WARM DAY, the temperature in a car can exceed 120° in a matter of minutes—even with the windows partially open. Your pet can quickly suffer brain damage or die from heatstroke or suffocation.
  • Walk your dog in the morning and evening: When the temperature is very high, do not let your dog linger on hot asphalt or concrete. Your pet’s body can heat up quickly, and sensitive paw pads can burn.
  • Know when your pet is in danger: Symptoms of overheating in pets include excessive panting or difficulty breathing, increased heart and respiratory rate, drooling, mild weakness, unresponsiveness, or even collapse.

Stay Informed

Register for ALERTJAX notifications so you can be informed when potentially dangerous heat impacts Duval County. 

Download and print our Extreme Heat Safety flyers to help vulnerable members of our community stay safe when temperatures rise. 

Extreme Heat Safety (English)
Extreme Heat Safety (Spanish)