Phoenix just hit 108°F in May. Not July. Not August. May. More than two million people across the Sun Belt are dealing with temperatures that used to be reserved for the peak of summer, and the actual peak is still two months away.
Extreme heat kills more Americans than hurricanes, tornadoes, and floods combined. It is the deadliest natural hazard in the country, and it is getting worse. Heat waves are lasting longer, hitting earlier in the season, and reaching cities that never had to think about them before. Yet most households have zero preparation for a sustained heat event.
This guide covers everything you need to protect your household when temperatures spike — from cooling gear and hydration strategies to backup power for brownouts and a clear five-step action plan. Whether you have central AC or not, whether you live alone or have kids and elderly parents to worry about, the moves you make before the heat arrives determine how safely you get through it.
Key Takeaways
- Extreme heat kills more Americans annually than any other weather event — over 1,500 deaths per year
- Heat index above 105°F is dangerous for everyone, not just the elderly or vulnerable
- Blackout curtains can reduce indoor temps by 5-10°F — cheap and immediate impact
- Brownouts spike during heat waves — a portable power station keeps your cooling running
- Dehydration starts before you feel thirsty — electrolytes matter more than just water
- Create one “cool room” in your home rather than trying to cool the entire house
Why Extreme Heat Is Underestimated
We prepare for hurricanes and tornadoes because they look dramatic on the news. Extreme heat does not get the same urgency — but it should. According to the CDC, heat-related deaths have increased steadily over the past two decades, with over 1,500 deaths per year in the United States alone. The real number is likely much higher because many heat deaths are classified as heart attacks or respiratory failures.
Here is what makes extreme heat especially dangerous:
- It affects everyone. Unlike flooding, which is location-specific, extreme heat impacts entire regions simultaneously.
- Infrastructure fails under sustained heat. Power grids buckle, roads buckle, and AC systems that run 24/7 break down — right when you need them most.
- The body reaches a breaking point. Once your core temperature exceeds 104°F internally, organ damage can begin within 30 minutes.
- Nighttime temperatures are rising faster than daytime. Your body needs cool nights to recover. When overnight lows stay above 80°F, cumulative heat stress builds day after day.
Cooling Your Home: The First Line of Defense
Your home is your shelter during a heat wave. The goal is to make it as cool as possible, keep it that way, and have backup plans when the power grid struggles. Start with the cheapest and most effective upgrades.
Blackout and Thermal Curtains
Blackout Thermal Curtains
This is the single highest-impact, lowest-cost upgrade you can make before a heat wave. Thermal-backed blackout curtains block up to 99% of sunlight and reduce room temperature by 5-10°F. Hang them on south- and west-facing windows — those get the most afternoon sun and heat gain. Close them before the sun reaches those windows and keep them shut until sunset.
Why We Like It
- Reduces room temperature 5-10°F immediately
- Cuts AC energy costs by up to 25%
- Works even without AC — blocks radiant heat
- Lasts for years, no maintenance
Keep in Mind
- Darkens the room (use lamps as needed)
- Must be sized properly to cover the full window
- Lighter colors reflect more heat than darker ones
Portable AC Units
Portable Air Conditioner
If you do not have central AC, or if your AC cannot keep up with extreme heat, a portable unit lets you cool one critical room effectively. Place it in your bedroom or living room — wherever your household spends the most time during peak heat. Modern portables with dual-hose designs are significantly more efficient than older single-hose models. Look for at least 10,000 BTU for a standard bedroom.
Why We Like It
- No installation — rolls from room to room
- Works in apartments and rentals
- Can cool a bedroom to sleeping temperature in 20 min
- Doubles as a dehumidifier
Keep in Mind
- Needs a window for exhaust hose
- Louder than window or central AC
- Uses 900-1,400 watts — significant power draw
Personal Cooling: Stay Cool When You’re on the Move
You cannot stay inside your cool room all day. Errands, commutes, outdoor work, and even just walking to your car mean exposure. Personal cooling gear has gotten surprisingly good and affordable.
Cooling Towels
Soak in water, wring out, and snap to activate. Cooling towels use evaporative technology to stay up to 30°F cooler than the ambient temperature for 2-3 hours. Drape one around your neck where major blood vessels run close to the skin. When it stops feeling cool, re-soak it and snap again. These are incredibly simple and genuinely effective.
Why We Like It
- Instant cooling — no batteries or power needed
- Reusable hundreds of times
- Lightweight and packable
- Under $15 for a multi-pack
Keep in Mind
- Less effective in very high humidity
- Needs re-soaking every 2-3 hours
- Not a replacement for shade and hydration
Portable Neck Fan
A wearable neck fan creates a constant breeze across your face and neck. It looks a little unusual, but once you try one during 100°F+ heat, you will not care how it looks. The bladeless designs are lightweight (under 10 oz), run for 6-12 hours on a charge, and make outdoor temperatures feel 8-12°F cooler through convective cooling.
Why We Like It
- Hands-free cooling all day
- Long battery life (6-12 hours)
- USB-C rechargeable
- Adjustable 3 speed settings
Keep in Mind
- Circulates hot air in extreme heat (pair with wet towel)
- Mild noise on highest setting
- Some models are heavier than others
Cooling Vest for Outdoor Work
If you work outdoors, exercise outside, or have to spend extended time in the heat, a cooling vest is the most effective personal cooling tool available. Evaporative vests are soaked in water and work like a full-body cooling towel. Ice-pack vests use frozen gel inserts for more intense cooling. Construction workers, delivery drivers, and athletes have used these for years — they genuinely work.
Why We Like It
- Core body cooling — most effective placement
- Evaporative versions need only water
- Ice-pack versions stay cold 2-4 hours
- Proven by outdoor workers in extreme heat
Keep in Mind
- Evaporative less effective in high humidity
- Ice-pack versions add weight
- Needs re-cooling after 2-4 hours
Hydration: More Than Just Drinking Water
Most people think hydration means drinking more water. That is part of it, but in extreme heat, you are losing electrolytes — sodium, potassium, and magnesium — through sweat at an accelerated rate. Drinking plain water without replacing electrolytes can actually make things worse by diluting the sodium your body needs to function.
Signs you are dehydrated (not just thirsty):
- Dark yellow urine (should be pale yellow)
- Dizziness or lightheadedness when standing
- Muscle cramps, especially in legs and abdomen
- Headache that does not respond to painkillers
- Fatigue and irritability beyond what the heat explains
Electrolyte Powder Packets
Keep a box of electrolyte powder packets in your kitchen and your go-bag. Mix one into a 16 oz bottle of water and drink throughout the day. Look for formulas with at least 500mg sodium, plus potassium and magnesium. Brands like LMNT, Liquid IV, and Drip Drop are all solid choices. Avoid the sugary sports drinks — you want electrolytes, not a sugar crash.
Why We Like It
- Replaces what sweat takes away
- Portable — fits in pocket or bag
- More effective than water alone
- Variety of flavors and formulas
Keep in Mind
- Some brands high in sodium for low-sodium diets
- Taste is personal — try a few brands
- Not a substitute for actual water intake
Backup Power: When the Grid Buckles
Here is the cruel irony of extreme heat: the moment everyone turns on their AC is the moment the power grid is most likely to fail. During the 2023 Texas heat wave, ERCOT issued multiple conservation appeals. California’s grid routinely strains above 110°F. Brownouts and rolling blackouts during heat waves are becoming more common, not less.
Losing power during a heat wave is not an inconvenience — it is a medical emergency, especially for elderly people, children, and anyone with heat-sensitive conditions. A portable power station gives you a lifeline.
EcoFlow Delta Pro 3
The Delta Pro 3 is the gold standard for home backup power. During a brownout, it can run a portable AC unit, a refrigerator, multiple fans, and phone chargers for 8-12 hours depending on load. Its 4,000W output handles virtually any household appliance. If you live in the Sun Belt and depend on cooling to stay safe, this is the unit to own.
Why We Like It
- Powers a portable AC for 4-6 hours continuously
- Expandable up to 48 kWh with add-on batteries
- 60-minute fast charging from wall outlet
- LiFePO4 battery rated for 3,000+ cycles
Keep in Mind
- Premium price at $2,499
- Heavy at 114 lbs — not easily moved
- Solar panels sold separately
Jackery Explorer 1000 v2
The Jackery 1000 v2 is the budget-friendly alternative that still gets the job done for essential cooling. It will keep battery-powered fans, phone chargers, lights, and a small fridge running for a full day. It will not power a portable AC, but combined with fans, cooling towels, and good home insulation, it keeps your household functional during a power outage.
Why We Like It
- Best value for essential backup power
- Weighs 25 lbs — actually portable
- LiFePO4 for long life and heat tolerance
- Simple interface, no learning curve
Keep in Mind
- Cannot power a portable AC unit
- Slower solar charging than EcoFlow
- Not expandable with extra batteries
Battery-Powered Fan
When the power goes out, a battery-powered fan is your most energy-efficient cooling option. Modern rechargeable fans run for 10-24 hours on a single charge and can be recharged from a portable power station or car charger. Keep at least one per bedroom. Combined with a damp cooling towel, a battery fan can make a 90°F room feel tolerable enough to sleep.
Why We Like It
- Ultra-low power consumption
- Long runtime on battery
- Clip-on or freestanding options
- Under $30 — buy several
Keep in Mind
- Air circulation only — does not cool air
- Less effective above 100°F without moisture
- Needs pre-charging before an event
For a deep dive on portable power stations including solar charging options, check out our complete portable power station guide.
Cooling Solutions Compared
| Feature | Portable AC | Window AC | Cooling Fan |
|---|---|---|---|
| Price | $350-500 | $150-350 | $20-40 |
| Cooling Power | 8,000-14,000 BTU | 5,000-12,000 BTU | Air circulation only |
| Installation | None — plug in and go | Window mount required | None |
| Mobility | Rolls room to room | Fixed in window | Carry anywhere |
| Power Usage | 900-1,400W | 500-1,200W | 20-50W |
| Works in Blackout | With large power station | No | Yes (battery models) |
| Renter-Friendly | Yes | Depends on lease | Yes |
| Best For | Cooling one room fast | Permanent room cooling | Supplemental airflow |
Your 5-Step Heat Wave Action Plan
When the forecast shows extreme heat coming, work through these five steps in order. Each builds on the one before it.
Prepare Your Cool Room (48 Hours Before)
Choose the room with the fewest exterior walls and windows. Hang blackout curtains. Set up your portable AC or position fans strategically. Move essentials into this room — water, snacks, chargers, medications, entertainment. This room is your base during peak heat hours (10 AM - 6 PM).
Stock Up on Hydration Supplies (48 Hours Before)
Buy or fill water containers — at least 1 gallon per person per day for 3 days. Stock electrolyte packets. Freeze water bottles to double as ice packs and drinking water as they melt. Fill your bathtub with cool water for emergency use (sponge baths, cooling cloths).
Charge Everything (24 Hours Before)
Fully charge your portable power station, battery-powered fans, phones, laptops, and portable chargers. If the grid goes down, you do not want to be at 40% on anything. Charge your car to full if you drive an EV — it can double as a cooling shelter with AC.
Know Your Cooling Centers (Now)
Find your nearest public cooling center today — before you need it. Libraries, community centers, malls, and some churches open as cooling shelters during heat emergencies. Write down addresses and hours. If your home AC fails during a heat wave, you need to leave, not wait it out. FEMA’s heat safety page has resources by state.
Check on Vulnerable People (Daily During Heat)
Call or visit elderly neighbors, relatives who live alone, and anyone without reliable AC — at least twice a day during extreme heat. Heat stroke can cause confusion, which means the person may not realize they need help. Do not assume someone is fine because they have not called. A 10-minute check-in can save a life.
Heat Illness: Know the Difference, Act Fast
The difference between heat exhaustion and heat stroke is the difference between a treatable condition and a medical emergency. Everyone in your household should know these signs.
Heat Exhaustion (Treatable at Home)
- Heavy sweating
- Cold, pale, clammy skin
- Fast, weak pulse
- Nausea or vomiting
- Muscle cramps
- Dizziness, headache, feeling faint
What to do: Move to a cool area immediately. Lie down and loosen clothing. Apply cool, wet cloths to neck, wrists, and forehead. Sip cool water with electrolytes. If symptoms do not improve within 30 minutes, seek medical attention.
Heat Stroke (Call 911 Immediately)
- Body temperature above 103°F
- Hot, red, dry skin — no sweating
- Rapid, strong pulse
- Confusion, slurred speech, unconsciousness
- Throbbing headache
What to do: Call 911 immediately. Move the person to the coolest area available. Cool them aggressively — ice packs on neck, armpits, and groin. Immerse in cool bath if possible. Do not give fluids if the person is confused or unconscious. Heat stroke can cause permanent organ damage or death within 30 minutes if untreated.
Emergency Preparedness Overlap
Heat waves rarely come alone. Extended extreme heat often triggers wildfire smoke events that make it dangerous to open windows for ventilation. Power outages during heat waves create cascading failures — no AC, no refrigeration, no phone charging. And many regions that face extreme heat also face hurricane season in the same months.
The good news: most of the gear in this guide overlaps with other emergency preparations. A portable power station is as valuable during a hurricane as during a heat wave. Battery fans, water supplies, and electrolytes are universal emergency items. Preparing for extreme heat is not separate from your broader emergency plan — it is your emergency plan.
How Prepared Is Your Household?
Take our free 3-minute Emergency Readiness Scan and get personalized recommendations based on your location, household size, and risk factors.
Take the Emergency Scan →Read: Hurricane Preparedness Checklist 2026
Quick-Reference Gear List
| Category | Item | Budget |
|---|---|---|
| Home Cooling | Blackout/thermal curtains (2-4 panels) | $50-160 |
| Home Cooling | Portable AC unit | $350-500 |
| Personal Cooling | Cooling towels (4-pack) | $12-15 |
| Personal Cooling | Portable neck fan | $25-35 |
| Personal Cooling | Cooling vest | $30-60 |
| Hydration | Electrolyte powder packets (30+) | $20-25 |
| Hydration | Water supply (3-7 days) | $10-30 |
| Backup Power | EcoFlow Delta Pro 3 or Jackery 1000 v2 | $599-2,499 |
| Backup Power | Battery-powered fans (2-3 units) | $60-90 |
| TOTAL ESTIMATED COST | $1,156-3,414 | |
That range is wide because you can scale to your situation. A renter in a mild climate might only need curtains, cooling towels, and electrolytes ($80). A family in Phoenix with an elderly parent needs the full setup. Match your preparation to your actual risk.
FAQ
The National Weather Service issues excessive heat warnings when the heat index reaches 105°F (40.5°C) or higher. At a heat index of 125°F+, heat stroke becomes highly likely even for healthy adults. However, danger starts well below these thresholds for children, elderly people, and those with chronic conditions. Any sustained period above 95°F (35°C) with high humidity requires active precautions — hydration, shade, and cooling strategies.
Use a combination of strategies: hang blackout curtains to block solar heat gain, use battery-powered fans to circulate air, place a bowl of ice in front of a fan for a DIY cool breeze, wear cooling towels around your neck, stay on the lowest floor of your home (heat rises), avoid using the oven or stove, drink ice water with electrolytes constantly, and take cool showers throughout the day. If indoor temps exceed 95°F and you cannot bring them down, go to a public cooling center.
Heat exhaustion: heavy sweating, cold and clammy skin, fast but weak pulse, nausea, muscle cramps, dizziness. Move the person to a cool area, apply cool cloths, sip water. Heat stroke is a medical emergency: body temperature above 103°F, hot and red skin with NO sweating, fast and strong pulse, confusion, and loss of consciousness. Call 911 immediately for heat stroke. The key difference — heat exhaustion involves sweating, heat stroke does not.
Set your AC to 78°F rather than blasting it at the lowest setting. Running AC at very low temperatures strains the unit, spikes your energy bill, and contributes to grid brownouts. Use ceiling fans alongside AC — they make 78°F feel like 72°F. Close blinds on sun-facing windows, seal air leaks, and avoid opening exterior doors. Blackout curtains alone can reduce indoor temps by 5-10°F, taking significant load off your AC system.
Install blackout or thermal curtains on south- and west-facing windows. Service your AC and replace filters. Seal gaps around doors and windows. Stock water (1 gallon per person per day), electrolyte packets, and cooling supplies. Charge a portable power station for brownout backup. Identify your nearest cooling center. Create a cool room — one room with curtains drawn, fan running, and minimal heat-generating electronics.