Rising temperatures threaten more than misery for the oldest Americans

Familiarity with the heat has led to coping strategies. Nati Guerrera, 88, from Miami, only comes out of her house at night. Virginia Rivera, 77, oversees the palm trees at her retirement home in downtown Orlando, Fla.

“You see the trees blowing in the wind, you can go outside and enjoy it,” says Ms. Rivera, who has a heart monitor and recently had a stroke. “If you open the door and the trees don’t move, stay inside.”

This year’s particularly intense heat “causes aches and pains,” she noted, adding, “It just cuts off your air and you can’t breathe.”

In another Orlando neighborhood, 67-year-old Veronica King said she leaves her air conditioner on even when she can’t afford it. “I need to figure out how to pay that bill,” she said, adding that she depends on machines to help her breathe. “When it’s hot, I can’t breathe.”

In Houston, where the heat index could reach 107 degrees on Sunday, Ms Lowry and her husband, Jasper, 72, have come up with a compromise. They have two cars, neither with working air conditioning. But they thought they could at least spare the money to fix it in one of them.

“I used to go out here and work in the garden, mow the lawn and work on the car,” said Mr Lowry, sitting in the wheelchair he has needed since suffering a stroke. “But I can’t do it anymore because it’s too hot.”

He stayed outside, watching over the man he’d hired to fix his car, waiting for the chance to turn it on and—finally—feel a breath of fresh air.

Abigail Geiger contributed reporting from Orlando, and Veronica Zaragovia from Miami