Safety guide
Heat wave safety
Heat kills more Americans each year than tornadoes, hurricanes, and floods combined. Every death is preventable. Here is what to know.
The stakes
- 2003 European heat wave: 70,000+ dead.
- 1995 Chicago heat wave: 739 dead in 5 days.
- 2021 Pacific NW heat dome: 800+ dead in US and Canada.
- US average: 700+ heat deaths per year.
- True total likely 10x reported (heat is often not on death certificate).
The three heat illnesses
Heat cramps
Muscle spasms from salt loss. Not dangerous itself. Warning sign.
Heat exhaustion
Heavy sweating, pale/cool skin, nausea, fatigue, dizziness. Body still functioning.
Heatstroke
Hot dry skin, confusion or unconsciousness, high body temp (103+°F). Body has stopped cooling. MEDICAL EMERGENCY.
When to worry
- Actual temperature 90°F+ with humidity 40%+.
- Heat Index 100+°F.
- Nighttime lows staying above 75°F (body cannot recover overnight).
- Poor air conditioning or none.
- Elderly, very young, chronic disease, or on certain medications.
- Outdoor work, athletics, exposure without shade.
- Impaired judgment (alcohol, drugs).
Prevention
- Stay indoors during peak heat (11 AM - 4 PM).
- Drink water even if not thirsty. Sports drinks for extended exertion.
- AVOID alcohol, caffeine, sugary drinks — all dehydrate.
- Wear loose, light-colored clothing.
- Wear a wide-brimmed hat outdoors.
- Take frequent breaks in shade or AC.
- Cool showers or wet cloths for surface cooling.
- Never leave children or pets in vehicles. Ever.
Cooling centers
- Libraries, community centers, malls all provide free AC.
- Some cities operate designated cooling centers during heat emergencies.
- Call 211 for local cooling center locations.
- Check on neighbors, especially elderly.
Treating heat exhaustion
- Move person to cool space.
- Loosen clothing.
- Apply cool wet cloths.
- Fan them.
- Sip water or sports drink slowly.
- Do NOT give aspirin or acetaminophen (they don't reduce heat body temp).
- If symptoms don't improve in 30 min: call 911.
- If symptoms worsen (mental status change, unconsciousness): call 911 immediately — this is heatstroke.
Treating heatstroke — MEDICAL EMERGENCY
- Call 911 immediately.
- While waiting: get person to cool space.
- Cool the body fast: cold water immersion, cold packs at armpits, groin, neck.
- DO NOT give fluids to unconscious person.
- DO NOT give alcohol rubs — makes it worse.
- Cool aggressively until body temp drops to 102°F.
- Body temp above 104°F for over 30 minutes causes permanent organ damage.
Heatstroke kills. If the person's mental status changes and body is hot with no sweating, treat as heatstroke even before confirmed.
The wet bulb temperature threshold
Beyond 35°C (95°F) wet bulb temperature, healthy adults cannot survive more than 6 hours of exposure — the body cannot cool itself.
As of 2026, brief exceedances of 35°C WBGT have been recorded in the Persian Gulf and northern India. Climate models predict expansion.
Athletic and outdoor safety
- Cross-country / football preseason: high risk August.
- NCAA and NFHS require WBGT-based practice modifications.
- Wrestlers cutting weight are at especially high risk.
- Marathoners in heat waves: DNF rate spikes above 78°F WBGT.
- Outdoor workers: OSHA has no formal heat standard but issues guidance.
- Some states (Cal/OSHA, Washington, Oregon) have mandatory heat rules for outdoor workers.
Regional risk
- Southwest / Death Valley — hottest, but dry heat is less deadly than humid heat.
- Midwest / South — Heat Index most extreme.
- Pacific NW — homes rarely have AC, deaths spike in heat domes.
- Northeast / cities — urban heat island effect.
- Coastal areas — cooler but humid.