Extreme heat
Extreme heat is the deadliest weather phenomenon in the U.S. Learn to recognize danger signs and protect yourself.
🌡️ What is the heat index?
The heat index combines temperature and humidity to show how hot it really feels. High humidity prevents sweat from evaporating, making it harder for the body to cool down.
Caution
80-90°F
Extreme caution
90-103°F
Danger
103-124°F
Extreme danger
125°F+
⚠️Alert types
Excessive heat warning
ExtremeHeat index 105°F+ for 2+ days or nights above 75°F. Danger of death without precautions.
Heat advisory
HighHeat index 100-104°F. Take precautions to avoid heat illness.
Excessive heat watch
ModerateExcessive heat possible in coming days. Prepare and make plans.
🏥Heat illnesses
😰 Heat exhaustion
- Heavy sweating
- Cold, clammy skin
- Weak, fast pulse
- Nausea, dizziness, headache
- Treatment: Cool place, water, wet compresses
🚨 Heat stroke (EMERGENCY)
- Body temp 103°F+
- Red, hot and DRY skin
- Fast, strong pulse
- Confusion, loss of consciousness
- CALL 911 IMMEDIATELY!
🛡️Recommendations
Hydration
- Drink water regularly, don't wait until thirsty
- Avoid alcohol, caffeine and sugary drinks
- Eat fruits with high water content
- Carry water bottle everywhere
Protection
- Wear light, loose, light-colored clothing
- Apply SPF 30+ sunscreen
- Limit outdoor activities 10am-4pm
- Seek air-conditioned places
Vulnerable groups
- Check on elderly and alone neighbors
- Never leave children or pets in vehicles
- Outdoor workers: frequent breaks
- People with chronic illness: extra care
☀️ Monitor conditions
Check heat alerts and forecasts to plan your activities safely.