Extreme Heat Safety: Your Body on High Temperatures
Key Takeaways
- Extreme heat kills more people in the U.S. than any other weather hazard — over 700 deaths each year.
- Certain medications, including common antidepressants, diuretics, and antihistamines, can make your body more vulnerable to heat.
- Heat stroke is a medical emergency: body temperature at or above 104°F with confusion or unconsciousness. Call 911 immediately.
- Electric fans alone won’t prevent heat illness when temperatures are in the high 90s. Air conditioning or cool water is needed.
- You can stay cool without AC: create a “cool corner,” use wet cloths on pulse points, and visit public cooling centers.
When the temperature climbs past 90°F, your body works overtime to keep you cool. But if you take certain medications or don’t have air conditioning, the heat can overwhelm your system. Here’s what you need to know about extreme heat safety — and how to protect yourself when the mercury rises.
Quick Answer: What Is Extreme Heat Safety?
Extreme heat safety means knowing how your body reacts to high temperatures, recognizing early signs of heat illness, and taking steps to stay cool — especially if you take medications that raise your risk. It’s about understanding the science behind overheating so you can act before it becomes an emergency.
What Happens to Your Body During Extreme Heat
Your body is built to keep its core temperature near 98.6°F. When it gets hot outside, your main cooling system kicks in: you sweat. As sweat evaporates, it carries heat away. Women’s hormonal cycles can also affect how your body regulates temperature — learn more in our guide to overheating in women.
But high humidity stops sweat from evaporating. Your cooling system slows. Your heart pumps harder to send blood to your skin. That’s why you feel your pulse race on a hot day.
If this goes on too long, you lose water and salt. You may feel dizzy, weak, or sick. That’s heat exhaustion. If you don’t cool down, your internal temperature can climb to dangerous levels. Heat stroke can damage your brain, heart, kidneys, and muscles within minutes.
Who’s at Higher Risk? Medications, Health Conditions, and Extreme Heat Safety
Many people don’t realize that common drugs can mess with your body’s cooling system. According to the CDC guidance on heat and medication interactions, several drug classes increase heat sensitivity:
- Diuretics (water pills) — like furosemide or hydrochlorothiazide — make you lose more fluid through urine, raising dehydration risk.
- SSRIs and SNRIs — such as sertraline (Zoloft), fluoxetine (Prozac), or duloxetine (Cymbalta) — can affect the part of your brain that controls temperature and sweating, sometimes making you sweat too much or too little.
- Antihistamines — especially older ones like diphenhydramine (Benadryl) — may reduce sweating. (A 2024 study in young adults found a single dose didn’t affect temperature, but the CDC still advises caution.)
- Beta blockers — such as metoprolol or atenolol — slow your heart rate, so your body can’t pump blood to your skin as well.
- Antipsychotics and tricyclic antidepressants — like quetiapine (Seroquel) or amitriptyline — can interfere with your brain’s thermostat, the hypothalamus.
If you take any of these, talk to your doctor before summer. Ask if you should adjust your dose during a heat wave. Never stop a medication on your own.
Other things that raise your risk: pregnancy, being over 65, having heart or kidney disease, being overweight, and having a sunburn (burned skin can’t sweat well). Summer also brings other health concerns worth knowing about, like our West Nile virus prevention guide for women.
Heat Exhaustion vs. Heat Stroke: How to Spot the Difference
Knowing the difference can save a life. Here’s what to watch for, according to the Mayo Clinic on heatstroke symptoms and emergency care:
Heat Exhaustion
- Heavy sweating
- Cool, moist, pale skin
- Dizziness, weakness, or fainting
- Fast, weak pulse
- Nausea or vomiting
- Body temperature above 100°F but below 104°F
What to do: Move to a cool place, loosen clothes, sip water or a sports drink. If you don’t feel better within an hour, get medical help.
Heat Stroke
- Body temperature at or above 104°F
- Hot, red, dry skin (or damp with exertion)
- Confusion, slurred speech, or unconsciousness
- Rapid, strong pulse
- Seizures
Call 911 immediately. While waiting, move the person to a cool area, remove extra clothing, and cool with cold water, ice packs on neck/armpits/groin, or a fan with misting. Do not give fluids if they are confused or unconscious.
Staying Cool Without Air Conditioning
Not everyone has AC. But you can still create a safe, cool space. Use these tips from the PBS News story on cooling without AC:
- Create a cool corner. Pick one room, close curtains, and use a fan. A basement or shaded room works best.
- Wet cloths on pulse points. Put cool, damp cloths on your wrists, neck, armpits, and feet. Evaporation cools the blood near your skin.
- Use fans smartly. Put a bowl of ice in front of a fan for a homemade cooling effect. But remember: above 95°F, fans alone won’t prevent heat illness — as Ready.gov explains.
- Take cool showers or baths. Even a few minutes under cool water lowers your core temperature.
- Visit public cooling centers. Libraries, malls, movie theaters, and community centers usually have AC. Some cities offer free bus rides to these centers.
- Look into LIHEAP. This program can help with cooling costs or a window AC unit.
Overnight cooling is key. When night temperatures stay above 75°F, your body doesn’t recover. The deficit builds each day. That’s the danger of a long heat wave.
Your Extreme Heat Safety Plan: What to Do Before and During a Heat Wave
A little planning goes a long way for extreme heat safety. Here’s a simple checklist:
Before a Heat Wave
- Check if your medications increase heat risk — talk to your doctor.
- Find cooling center locations and hours.
- Stock water (at least 1 gallon per person per day) and electrolyte drinks.
- Make sure your AC or fans work.
- Have a thermometer that reads up to 110°F.
During a Heat Wave
- Stay indoors during peak heat (usually 3 p.m. to 6 p.m.).
- Drink water frequently, even if not thirsty. Dark urine means drink more.
- Wear loose, light-colored cotton, linen, or hemp clothes.
- Avoid sugary, caffeinated, and alcoholic drinks — they dehydrate you.
- Use SPF 30+ sunscreen if you go out. Sunburn hurts sweating.
- Check on older neighbors and family twice a day.
- Never leave kids or pets in a parked car, even for a minute.
Frequently Asked Questions
Can I exercise outside if I take an SSRI?
Exercise in the heat while on SSRIs needs extra care. Your meds may affect temperature control. Exercise early or late in the day, drink water, and watch for dizziness or fatigue.
What if I have no AC and can’t afford it?
Find free cooling centers: libraries, malls, community centers. Some cities offer free rides. Also check if you qualify for LIHEAP help with cooling costs.
Is a cool shower safe when overheated?
Yes. A cool (not cold) shower or bath helps lower body temperature. If you start to shiver, the water may be too cold — warm it slightly.
The Bottom Line
Extreme heat safety is about knowing what your body goes through and taking steps before you’re in danger. Understand your medication risks, recognize early heat illness signs, and have a plan to cool off without AC.
Heat waves are becoming more common. But with knowledge and preparation, you can protect yourself and your loved ones.
