AC-dependent US homes turn deadly when power fails
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- Henry Galson's 1947 invention of a low-cost window air conditioner — "the people's air conditioner" — transformed American building by enabling mass-produced suburbs in hot Sunbelt climates; AC's postwar rollout cut the likelihood of an American dying on a scorching day by 80%.
- Researchers estimate a two-day blackout during a Phoenix heat wave could kill roughly 12,800 people — about 1% of the city's population — while requiring emergency care for half the city.
- Passive design fixes could slash that toll: planting trees to shade half of Phoenix's streets would cut blackout deaths by 27%, and painting every building with a reflective "cool roof" would cut deaths by 66%.
- U.S. power outages have doubled over the past two decades, and after Hurricane Beryl knocked out Texas power in 2024, dozens to hundreds died from heat-related causes — possibly making the outage deadlier than the storm itself.
- Ancient cooling techniques — Greece's whitewashed cliffside buildings, Iran's badgir wind catchers, and Malaysian stilt homes — kept structures livable for millennia, and U.S. groups like Phius and Passive House Massachusetts are now reviving them.
- Up to a quarter of Arizonans who die from indoor heat live in mobile homes, whose thin walls and poor insulation make them especially deadly without AC; among the dead: Stephanie Pullman, 72, who died in 2018 a day after her electricity was cut over a $51 unpaid bill, and Patricia Miletich, 70, who died in June 2024 inside an RV whose busted AC was blowing 110-degree air.
- Western Europe's record-shattering heat wave last month killed at least 1,300 people, exposing how even centuries-old passive cooling systems are no longer sufficient for what experts call a "new world of heat."
Why it matters: AC-dependent American buildings become lethal the moment the grid fails, with Phoenix modeled as losing up to 12,800 people in a two-day blackout — a real risk given U.S. power outages have already doubled in two decades. Simple, cheap fixes like cool roofs and street trees could cut that death toll by more than half, but no building code requires them.
