Extreme Heat Emergency Preparedness: How to Stay Safe When the Temperature Spikes
Heat kills more Americans every year than any other weather event. More than hurricanes, more than tornadoes, more than floods. The Centers for Disease Control reports that extreme heat causes over 1,300 deaths in the United States each year, and that number has been climbing every decade. The 2021 Pacific Northwest heat dome pushed temperatures above 115 degrees Fahrenheit in cities that had never seen anything close to that. Hundreds of people died. Most of them were at home.
This is not a problem that only affects people in the desert Southwest. Heat waves now hit cities and regions that have little experience managing them and few resources for dealing with them. If you are not prepared, a heat emergency can become life-threatening faster than almost any other disaster scenario.
This guide covers everything you need to know: how to recognize heat emergencies in yourself and others, how to stay cool without air conditioning, the gear that actually helps, and how to build a heat emergency kit before the next wave hits.
Why Trust This Guide?
This article was researched and reviewed by contributors with hands-on experience in emergency preparedness. They have tested gear, built real systems, and lived through situations where these skills actually mattered.
Why Heat Is the Deadliest Weather Hazard
Most natural disasters give some warning. A tornado shows up on radar. A hurricane has a projected path. A flood has a river stage number. But a heat wave is invisible. You cannot see it. You cannot hear it. It does not look like anything is wrong. That invisibility is exactly what makes it so dangerous.
The human body is designed to maintain a core temperature of around 98.6 degrees Fahrenheit. When the air around you is 100 degrees or higher, especially with high humidity, your body has to work very hard to stay cool. It does this mainly through sweating. But if you are elderly, very young, dehydrated, ill, taking certain medications, or simply not acclimatized to the heat, that cooling system can fail faster than you expect.
Heat illness progresses in stages. The first signs are easy to miss or dismiss. By the time someone is clearly in trouble, they may already be in a medical emergency. Knowing the stages and acting early is what keeps heat stress from becoming heat stroke.
The Three Stages of Heat Illness
Understanding the difference between heat cramps, heat exhaustion, and heat stroke is the single most important thing you can learn from this guide. These are not the same thing, and the right response is different at each level.
Heat Cramps
Heat cramps are muscle spasms, usually in the legs, arms, or abdomen. They happen when you sweat out a lot of fluids and electrolytes without replacing them. They are painful but not immediately dangerous on their own. What they signal, though, is that your body is under heat stress.
What to do: Move to a cool or shaded area. Drink water or a sports drink with electrolytes. Rest. Stretch the cramping muscles gently. Do not return to strenuous activity until the cramps have been gone for at least an hour.
Heat Exhaustion
Heat exhaustion is the warning alarm your body sends before heat stroke. The signs include heavy sweating, cold and pale or clammy skin, fast and weak pulse, nausea, muscle cramps, weakness, dizziness, and headache. A person may feel faint. They may still be sweating, which means their cooling system is still working but struggling.
What to do: Move the person to a cool place immediately. Have them lie down with their legs elevated if possible. Remove excess clothing. Apply cool wet cloths to their skin. Have them drink cool water if they are conscious and not vomiting. Fan them. If they vomit, they cannot keep fluids down, or they do not improve within 30 minutes, call 911.
Heat exhaustion must be taken seriously. Left untreated or if the person continues to push through it, heat exhaustion can progress to heat stroke within minutes.
Heat Stroke
Heat stroke is a life-threatening emergency. Call 911 immediately.
The signs of heat stroke include a body temperature above 103 degrees Fahrenheit, hot and red skin that may be dry or damp, a fast and strong pulse, confusion, slurred speech, loss of consciousness, and seizures. Unlike heat exhaustion, a person in heat stroke may have stopped sweating entirely, which means the cooling system has failed.
What to do while waiting for 911: Get the person to the coolest place available. Pack ice or cold packs around their neck, armpits, and groin, where blood vessels are close to the skin. Apply cool wet cloths to the entire body. Fan aggressively. If you have a tub, immersion in cool water is the most effective cooling method available. Do not give fluids to someone who is confused or unconscious.
Heat stroke can cause permanent organ damage or death if core temperature stays elevated for too long. The goal is to lower body temperature as fast as possible before emergency services arrive.
Who Is Most at Risk
Heat affects everyone, but some people are in significantly more danger than others. Knowing who is at high risk in your household or neighborhood helps you plan ahead and check on the right people during a heat emergency.
People over 65: The body’s ability to regulate temperature decreases with age. Older adults often do not feel thirst as strongly, so they may become dehydrated without realizing it. Many also have conditions or take medications that affect sweating or circulation.
Infants and young children: Small bodies heat up much faster than adult bodies. Children cannot communicate that they are overheating the way adults can. Never leave a child alone in a parked car, even for a few minutes.
People with chronic medical conditions: Heart disease, kidney disease, diabetes, obesity, and respiratory conditions all increase heat risk. The heart has to work harder when the body is trying to cool down, which puts people with cardiovascular conditions at special risk.
People taking certain medications: A long list of common medications affects heat risk. These include diuretics (water pills), antihistamines, beta blockers, antidepressants, antipsychotics, and anticholinergics. If you or a family member takes any regular prescription medication, look it up specifically for heat-related warnings or ask a pharmacist.
Outdoor workers and athletes: Construction workers, landscapers, farm workers, and anyone who exercises outside in the heat faces significant risk. Heat illness is one of the most common and preventable causes of death among outdoor workers.
People without air conditioning: This is the biggest single risk factor in urban heat emergencies. Many of the deaths in the 2021 Pacific Northwest heat dome happened in apartments and homes without AC, often among people who did not know how to stay cool without it.
People who are alone: Isolation means no one notices when you stop making sense, stop drinking water, or stop responding to knocks at the door. During a heat wave, checking on people who live alone is not just a kind gesture. It saves lives.
Staying Cool Without Air Conditioning
Air conditioning is the most effective tool for surviving a heat emergency. If you have it, use it and keep it running during a heat wave. But not everyone has AC, and power outages can knock it out exactly when you need it most. These strategies work when AC is not available.
Block the Heat Before It Gets In
The most effective thing you can do in a home without AC is to prevent the heat from entering in the first place.
Close windows and blinds on all sun-facing sides of your home during the day. A closed window blocks direct solar radiation from entering. Heavy blackout curtains are much more effective than thin curtains. If you have south-facing or west-facing windows that get afternoon sun, covering them can drop indoor temperatures by 10 to 20 degrees compared to leaving them open.
Open windows at night when outdoor temperatures drop below indoor temperatures. Create cross-ventilation by opening windows on opposite sides of the home and using fans to draw cool night air through.
Keep interior doors between hot and cool rooms closed during the day to contain cooler air in shaded areas.
Use Fans Strategically
A fan does not cool the air. It cools people by increasing evaporation of sweat from the skin. This means fans are much more effective when you are in the room with them and when there is still some temperature difference between indoors and outdoors.
At temperatures above 100 degrees Fahrenheit with high humidity, fans can actually increase heat stress by moving hot, humid air over the body without enough evaporative cooling to compensate. Know when to stop relying on fans alone and seek a cooler environment.
A box fan in a window, pointed outward on the hot side of the house, can pull hot air out. Another fan or open window on the cool side brings cooler air in. This works best in the evening when outdoor temps have dropped.
The O2COOL battery-powered fan runs on D batteries and does not require electricity, making it essential for power outages. For longer outages, a portable battery station can power a larger fan for extended periods.
Cool Your Body, Not the Room
When it is too hot to cool the entire room, focus on cooling your body directly.
Wet a cloth, bandana, or cooling towel and apply it to your neck, wrists, and the inside of your elbows. These areas have blood vessels close to the skin, and cooling them brings down core temperature faster than cooling your forehead or arms.
Take cool showers or baths. Even a five-minute cool rinse lowers core temperature and provides real relief. You do not need to use cold water. Cool water is more tolerable and still very effective.
Fill a spray bottle with water and mist your skin. A small battery-powered misting fan combines this effect with airflow. The Evapolar personal air cooler uses water evaporation to cool a small personal space and runs on USB power.
Wear loose, lightweight, light-colored clothing. Light colors reflect solar radiation rather than absorbing it. Cotton and moisture-wicking fabrics allow sweat to evaporate better than synthetic materials.
Identify Cool Spaces Before You Need Them
Know where you can go if your home becomes dangerously hot. Many cities open official cooling centers during heat emergencies. Call your city or county emergency management office to find your nearest cooling center.
Libraries, shopping malls, grocery stores, community centers, and movie theaters are air-conditioned public spaces where you can spend hours at no cost or low cost. Make a list of these locations now, including their hours, and save it in your phone.
If you have a car with working AC, it is a refuge. Park in shade when possible. Run the AC before getting in so you are not sitting in a hot vehicle waiting for it to cool.
The Best Cooling Gear for Heat Emergencies
Having the right gear before a heat wave is the difference between discomfort and danger. These are the items worth having on hand.
Cooling Vests and Wraps
A personal cooling vest uses ice packs or evaporative cooling to lower your body’s core temperature directly. They are widely used by outdoor workers, firefighters, and athletes, and they are genuinely effective.
The Ergodyne Chill-Its 6665 evaporative cooling vest soaks in water for one to two minutes and then provides cooling for hours as the water slowly evaporates. It does not require ice or refrigeration, which makes it ideal for emergencies when power is out. It is lightweight enough to wear while moving around and doing tasks.
For more aggressive cooling, phase-change vests contain materials that absorb heat as they melt, maintaining a specific temperature longer than ice alone.
Cooling neck wraps and wristbands work on the same evaporative principle. The Mission Enduracool cooling towel activates with water, wrings out, and stays cool for up to two hours. It can be rewet and reused as many times as needed.
Portable Battery Fans
During a power outage in a heat wave, a battery-powered fan is essential. Look for one with enough runtime to get through the night.
The OPOLAR battery-operated fan runs up to 35 hours on a charge, has three speed settings, and charges via USB. It is small enough to put on a nightstand and powerful enough to provide real airflow while sleeping. Keep it charged during heat wave season the same way you would keep a flashlight charged.
For the whole family, a larger USB desk fan powered by a portable battery station gives multiple people access to cooling airflow through the night.
Portable Power Stations
If you have medical equipment, a CPAP machine, or medications that need to stay refrigerated during a heat wave, a portable power station gives you the ability to keep essential things running even if the grid goes down.
The Jackery Explorer 300 Plus holds 288 Wh of capacity, weighs about 7.5 pounds, and can run a small fan for many hours. It can be recharged from a car’s 12-volt outlet, which keeps it useful even in extended outages. For larger needs like running a small window AC unit, a higher capacity model like the EcoFlow DELTA 2 can handle that load.
Electrolyte Supplements
Drinking plain water during heavy sweating is not enough. Sweat contains sodium, potassium, magnesium, and other electrolytes. Replacing only water without replacing electrolytes can cause a condition called hyponatremia, or low sodium, which causes weakness, headache, confusion, and in severe cases, can be life-threatening.
Electrolyte packets make it easy to keep your body properly hydrated during a heat event.
LMNT electrolyte packets contain 1,000 mg of sodium, 200 mg of potassium, and 60 mg of magnesium per packet, without sugar or artificial coloring. They dissolve in water and actually replace what your body loses through sweating.
Liquid IV hydration multiplier uses a different approach, helping water absorb into the bloodstream faster through a cellular transport mechanism. Both are worth keeping in your heat emergency kit.
Stock at least a week’s worth of electrolyte packets per person before heat season starts.
Cold Packs and Ice Tools
Reusable gel ice packs have many uses during a heat emergency: cooling the neck and wrists, treating heat cramps, and bringing down core temperature in someone showing signs of heat exhaustion.
Keep a set of flexible reusable gel ice packs in your freezer during heat season. They stay colder longer than ice because they hold temperature as a gel rather than melting water. If the power goes out, a well-insulated cooler filled with these packs stays cold for 24 to 48 hours.
For field use, single-use instant cold packs activate by squeezing without needing refrigeration. They are not as cold or as long-lasting as frozen gel packs, but they work anywhere. Keep a box of instant cold packs in your heat emergency kit.
Thermometers and Heat Monitoring
You cannot manage what you cannot measure. A digital thermometer lets you monitor both body temperature and room temperature, which are the two most important numbers during a heat emergency.
Know that outdoor temperature is only part of the picture. Humidity matters enormously. A 95-degree day with 90 percent humidity has a heat index (what it actually feels like to the body) above 130 degrees. A digital weather station or hygrometer that shows temperature and relative humidity lets you calculate the real heat risk in your environment.
The AcuRite digital thermometer and humidity monitor costs about $20 and shows both temperature and humidity at a glance. Put one in your bedroom and monitor it during heat waves.
Sun Protection for Outdoor Use
If you have to be outside during a heat emergency, the right sun protection significantly reduces heat load.
A wide-brim sun hat with a UPF 50 rating blocks nearly all UV radiation from reaching your head, neck, and face. Sunburn reduces your body’s ability to sweat effectively, which makes sun protection not just a comfort issue but a safety issue during extreme heat.
UV-protective long-sleeve shirts made from lightweight wicking fabric cover more skin than a t-shirt while actually keeping you cooler than bare skin in direct sunlight, because they protect against direct solar radiation.
A pop-up shade shelter creates a shaded rest area for outdoor workers, outdoor events, or if you are spending time outside during a heat wave.
Building Your Heat Emergency Kit
Protecting Vulnerable People During a Heat Wave
Infants and Young Children
Children’s bodies heat up faster than adult bodies because they have a higher surface-area-to-body-mass ratio and a less developed thermoregulation system. They also cannot tell you they are overheating, which means you need to watch for signs rather than wait for them to complain.
Never leave an infant or young child in a parked vehicle, not even for a few minutes. A car parked in the sun can reach 130 to 170 degrees inside within 30 to 60 minutes. Children die in hot cars every year, and it can happen accidentally. If you see a child alone in a hot car, call 911 immediately.
Keep infants as cool as possible. Dress them in light single layers. Use a fan to circulate air but do not aim it directly at an infant. Offer breast milk or formula more frequently. Watch for signs of overheating: red flushed skin, crying that does not resolve, rapid breathing, and refusal to feed.
For toddlers and older children, offer cool water or diluted sports drinks frequently even if they do not ask. Keep them indoors during the hottest part of the day, generally 10 AM to 4 PM. Sprinklers, kiddie pools, and cool baths are effective and enjoyable ways to manage heat in children.
Elderly Family Members and Neighbors
People over 65 face much higher heat risk than the general population, and many of them live alone. The single most effective thing you can do during a heat wave is check on elderly neighbors and relatives at least twice a day.
Air conditioning access is the primary protective factor. If an elderly person does not have AC or their AC has failed, help them get to a cooling center, a family member’s home, or another air-conditioned space. Do not assume they will reach out for help themselves. Heat affects cognition, and people in early stages of heat illness often do not recognize how seriously their judgment has been impaired.
If an elderly person is on a fixed income or cannot afford to run AC, know that most utility companies have programs to prevent shutoffs during heat emergencies and some offer assistance with bills. Local Area Agencies on Aging often have resources as well.
People with Medical Conditions and Medications
If you or a family member takes prescription medications, review the list with a pharmacist specifically for heat-related warnings. Common medications that increase heat risk include:
- Diuretics (furosemide, hydrochlorothiazide): reduce fluid in the body, increasing dehydration risk
- Anticholinergics: reduce sweating
- Beta blockers: reduce the heart rate response to heat, making it harder for the body to compensate
- Antidepressants and antipsychotics: can impair the body’s temperature regulation and thirst sensation
- Antihistamines: reduce sweating in some people
If a medication cannot be safely stopped, the response is to be more aggressive about staying cool, staying hydrated, and monitoring for signs of heat illness.
People with heart disease face specific danger during heat waves because the heart has to work harder when the body is trying to cool down. If you have heart disease or care for someone who does, heat waves require the same level of attention as a high-risk weather event.
For medications that require refrigeration, a power outage during a heat wave is a double threat: the medication may be compromised at the same time the person needs it most. Know the temperature range your medication can tolerate. Many insulins, for example, remain stable at room temperature for 28 days once opened but should not exceed 86 degrees Fahrenheit. A portable battery station powering a small mini-fridge or a well-insulated cooler with gel ice packs can protect temperature-sensitive medications during an outage.
Pets
Pets cannot sweat the way humans can and are highly vulnerable to heat stroke. Dogs pant to cool themselves, and in very hot air, panting provides limited cooling. Heat stroke in dogs can occur in minutes and is frequently fatal without rapid treatment.
Never leave a dog in a parked car, even with the windows cracked. Even on a mild day (75 degrees Fahrenheit), a car can reach over 100 degrees inside within 20 minutes.
Walk dogs in the early morning or evening when pavement temperatures are safe. Asphalt in direct sun can reach 150 degrees Fahrenheit. Test pavement with the back of your hand. If you cannot hold your hand to the pavement for 10 seconds, it will burn your dog’s paws.
Provide access to shade and fresh cool water at all times. A small kiddie pool gives dogs an easy way to cool off. If a dog is showing signs of heat stroke (excessive panting, drooling, weakness, vomiting, collapse), cool the animal with cool but not ice-cold water, focus on the neck and belly, and get to a veterinarian immediately.
For cats and indoor pets, keep the home as cool as possible. Fill a shallow bowl with ice for pets to drink from or lie near.
Heat Safety in Vehicles
Vehicles become dangerous fast in high heat. The interior of a car can rise 20 degrees above the outside temperature within 10 minutes and continue climbing after that. Before getting in a hot car:
- Open all doors and let the hot air escape for 60 to 90 seconds before getting in
- Turn the AC on full and direct the vents toward you
- Check the temperature of metal components like seat belt buckles before children touch them; metal surfaces in a hot car can cause contact burns
- In very hot weather, consider using a windshield sunshade to reduce heat buildup when parked
For longer drives in extreme heat, carry extra water, an electrolyte source, and a manual window breaker in case of emergency. Know where the nearest hospitals and cooling centers are along your route.
Hydration During a Heat Wave: How Much Is Enough
The standard advice to drink eight glasses of water per day was not designed for extreme heat. During a heat wave when you are sweating heavily, adults may need significantly more.
A practical rule during active heat exposure: drink enough that your urine stays light yellow (like lemonade) rather than dark yellow (like apple juice). Dark urine is a reliable early sign of dehydration.
Drink water before you feel thirsty, especially if you are elderly or caring for elderly people, because the thirst mechanism becomes less reliable with age. Thirst means you are already behind.
Avoid alcohol and caffeine in excessive amounts during heat waves. Both increase fluid loss. If you drink coffee in the morning, that is fine, but do not use caffeinated beverages as your primary hydration source during a heat event.
Eat water-rich foods. Watermelon, cucumber, strawberries, and celery all contain high water content and contribute to hydration. Cold fruit from the refrigerator also provides a mild cooling effect when eaten.
A Simple 7-Day Heat Wave Action Plan
Monitoring Heat Alerts Before They Arrive
The National Weather Service issues heat watches, heat advisories, and excessive heat warnings before extreme heat events. These mean different things and call for different levels of response.
Heat Advisory: Daytime heat index between 100 and 105 degrees expected. Hot and potentially dangerous conditions. Take extra precautions if you work outdoors or have risk factors.
Excessive Heat Watch: Excessive heat is possible in the next 24 to 48 hours. Start preparing now. Stock water, check your kit, and make a plan for cooling center access.
Excessive Heat Warning: Dangerous heat is happening or will happen within the next 12 hours. Heat index above 105 degrees. Dangerous to most people, including those who are young and healthy. Take every precaution. Minimize outdoor activity.
Sign up for your local emergency alert system. Most counties send heat warnings by text message or email. Search your county name plus “emergency alert registration” to find the sign-up page. Also check the National Weather Service at weather.gov and the Weather Channel app, both of which show heat advisories by location.
The NOAA Weather Radio system broadcasts updated weather alerts around the clock, including heat warnings. The Midland ER310 and similar weather radios receive these broadcasts automatically, including an alarm tone that wakes you if a warning is issued while you are asleep.
Outdoor Workers and Athletes: Special Considerations
People who have to be outside during extreme heat need a more structured approach. The body can acclimatize to heat to a degree, but that process takes 10 to 14 days and is not a substitute for protection.
The work-rest-water rule: During a heat wave, take regular rest breaks in shade or a cool environment. Drink at least 8 ounces of water every 15 to 20 minutes during outdoor work. Do not wait until you are thirsty.
Buddy system: Do not work alone in extreme heat. A partner can notice signs of heat illness that the person experiencing it may not recognize. This is especially important because impaired judgment is one of the early signs of heat exhaustion and heat stroke.
Early warning signs to take seriously: Headache, heavy fatigue, weakness, and feeling flushed are signs to stop activity, get to a cool place, and hydrate immediately. Pushing through these warning signs is how heat emergencies happen.
Time-of-day awareness: Plan outdoor work during early morning hours before 10 AM when possible. Avoid the hottest part of the day. If work must happen in the afternoon, maximize shade use and rest frequency.
Recovery matters too: After a hot day, allow your body to cool completely before sleeping. A lukewarm shower lowers core temperature faster than a cold one because cold showers cause blood vessels to constrict and can actually slow heat transfer. Drink fluids before bed. Sleeping in a room that stays above 80 to 85 degrees prevents full physiological recovery, which means the next hot day starts from an already-stressed baseline.
The One Step to Take This Week
If you have read this entire guide, here is the single most important action: check whether your most vulnerable neighbors, family members, or contacts have reliable cooling.
Call or visit an elderly parent, a neighbor you know lives alone, or anyone in your life who falls into a high-risk category. Ask directly whether they have air conditioning and whether it is working. Ask whether they know where their nearest cooling center is. Offer to drive them if they need to go.
This costs nothing. It takes 10 minutes. And it is the kind of action that, during a serious heat wave, saves lives.
Then spend 30 minutes building your heat kit from this guide. Order the cooling vest, the electrolyte packets, the battery fan. They will arrive before the next heat wave, and you will be prepared in a way that most of your neighbors are not.
Heat kills quietly. It shows up without the drama of a storm. It does not knock your house down or flood your street. It just makes the temperature climb until the people inside stop being okay. Preparation is the only defense, and the time to prepare is before the heat arrives.
Stay cool, stay hydrated, and look out for the people around you.