How to stay cool when the power's out in a heat wave
Without air conditioning, heat can become a medical emergency
Losing air conditioning in extreme heat is a genuine medical hazard, not just discomfort: heat exhaustion can become heat stroke, which the National Weather Service calls a severe medical emergency in which delay can be fatal. Older adults, young children, people with chronic illness, and anyone on certain medications are most at risk.
Know heat exhaustion vs heat stroke
Per the National Weather Service, drawing on the CDC's first-aid guidance: heat exhaustion = heavy sweating, cool/pale/clammy skin, fast weak pulse, nausea, dizziness, headache — move to a cool place, sip water, loosen clothing, use cool cloths, and get medical help right away if the person vomits or the symptoms get worse or last longer than an hour. Heat stroke = body temperature above 103 °F, hot/red/dry or damp skin, a rapid strong pulse, throbbing headache, confusion, or loss of consciousness — this is a 911 emergency: move the person somewhere cooler, help lower their temperature with cool cloths or a cool bath, and do not give fluids.
Get to air conditioning
The CDC's advice is to use air conditioning or find a place that has it: dial 2-1-1, or contact your local health department or emergency-management agency, for open cooling centers. A library, a mall or a friend's home with power works too. And a fan is not a substitute once it is hot indoors: the CDC says to use fans only while indoor temperatures are below 90 °F, because above that a fan can increase body temperature.
Hydrate and slow down
Keep water with you and drink it through the day; the CDC suggests limiting drinks high in sugar, sodium, caffeine and alcohol, and checking your urine color — light yellow or clear usually means you are drinking enough. Wear light, loose clothing, stay out of direct sun in the coolest room you have, and skip strenuous activity during the hottest hours. Wet cloths on the neck, wrists, and ankles, or a cool shower, shed heat fast.
Check on the vulnerable — and pets
Check on family, friends and neighbors, especially anyone with chronic medical problems or who lives alone, and check on pets, per the CDC. Pets need shade and water too.
Engineer one cool room
Choose the coolest, most shaded room, cover sun-facing windows with drapes or shades, and keep exterior doors shut during the heat of the day. If nights run cooler, ventilate hard after sunset — cross-breeze with windows on opposite sides — then close up at sunrise to trap the cool. Don't count on a battery fan as your main cooling: Ready.gov warns that fans create air flow and a false sense of comfort but do not reduce body temperature, and the CDC's 90 °F limit above still applies.
Food and medication in the heat
The refrigerator windows don't get friendlier in a heat wave — keep doors closed and move must-keep items to a cooler with ice early rather than late. Refrigerated medications (insulin is the common case) need a plan from your pharmacist before summer: know each medicine's out-of-fridge tolerance and have a cooler dedicated to it.
Powering cooling without new dangers
Two mistakes add new dangers in the heat: a generator run too close to open windows (carbon monoxide — see the generator rules) and an overloaded extension cord feeding a window air conditioner (the CPSC says each cord's wattage rating must exceed the total of everything plugged into it). A battery power station makes no exhaust, so it can run fans and phones indoors; before counting on one for a window air conditioner, check the air conditioner's power draw against the station's rating.
Getting through the night
Heat peaks in the late afternoon, but stay alert overnight too: asleep, you can't notice warning signs. Before bed: a cool shower or bath, water within reach, a battery fan aimed across you only if the room is below 90 °F (above that, the CDC says a fan can raise body temperature), and the household together in the coolest room. If the heat-stroke signs above appear in anyone — confusion especially — treat it as the emergency it is, at any hour.
Cars are ovens
Per the National Weather Service, it is never safe to leave a child, a disabled person or a pet locked in a car, even in winter, and a child who gets into a hot car can die in 10 minutes. Leave no one in a vehicle during a heat event, even briefly, even with windows cracked.
Plan around the restoration time
If the outage will be long and the heat is dangerous, leaving for a cool place is the safe call: the Red Cross says to evacuate if your home is too hot, and that communities often provide cooling centers. Check your address for the restoration outlook and set a free alert for when the outage in your area looks mostly restored.
General safety information drawn from the public sources linked above, not medical, electrical or legal advice for your situation. In an emergency, call 911.