23.6 Summer heat without air conditioning: the biggest risk in warm climates

In areas with hot summers, a long blackout in July or August can be more dangerous than one in winter. After Hurricane Beryl (2024), at least seven deaths were attributed to heat illness from lack of air conditioning during the blackout. A closed-up apartment accumulates heat day after day, and the body does not recover if the nights do not cool off either. The basics of heat (heat index, signs, and first aid) are in chapters 7 and 10; here is the plan for days or weeks without air conditioning.

Layered cooling plan

1. Block the sun before it gets in. Curtains closed early on the east side in the morning and the west side in the afternoon. Reflective film, light-colored sheets, or cardboard with aluminum foil facing out, on the inside of the glass, on the hottest windows.
2. Ventilate only when it is cooler outside than inside. Use an indoor thermometer and an outdoor one. Open up at night and in the early morning, close mid-morning. Put a fan in one window blowing air out and open another on the opposite side to create a cross breeze. Ground-floor security: open only windows with stops or bars, and never leave windows open without someone awake.
3. Create a cool room. The room with the least sun and the fewest exterior walls. Everyone sleeps there, pets included. Concentrate the fans there.
4. Cool the body, not the air. Damp cloths on the neck, armpits, and groin; feet in a tub of water; short showers with water from your non-drinking reserves (chapter 3). When the temperature is in the high 90s °F (36–37 °C), a fan alone does not prevent heat illness: combine it with water on the skin.
5. Reduce indoor heat. Do not cook indoors during the hot hours; use the camp stove outside and away from the building (chapter 22). Turn off everything that gives off heat.
6. Adjust the schedule. Physical activity and outings before 10 a.m. and after 7 p.m. Nap during the hottest hours.
7. Have a cool-refuge plan. Cooling centers run by your city or county (check their website or call 311 if your city has it), libraries, churches, or relatives' homes in areas with power. Take turns so the most vulnerable spend the worst hours there.
8. The car as a last resort. A few minutes of car air conditioning can lower the temperature of a person at risk, always outdoors, with the car running only while someone is awake, and watching the gasoline. Never in a covered or enclosed parking structure.

Pets in the heat

• Cool water in two or more bowls, in the cool room. Figure the baseline water by their weight (~0.2 gal / 0.75 L a day for a 15 lb / 7 kg dog); more in the heat.
• Walks only at dawn and dusk; check the pavement with the back of your hand.
• A damp towel on the floor for them to lie on; never ice-cold water.
• Signs of heat stroke: intense panting, drooling, very red gums, weakness, vomiting. Shade, cool water on the body, and a veterinarian (chapter 10).
• If you evacuate to a cooling center, ask beforehand whether they accept pets.

And if it's winter

In Winter Storm Uri (2021), nearly two out of three deaths were from hypothermia. A long blackout in a freeze calls for the opposite plan: a single room, layers, blankets, sleeping bags, and never heating with the gas stove, grills, or generators indoors. See chapters 9, 10, and 14.