For Europe’s Older Population, Heat Is the New Covid

As a light, hot breeze blew through her living room and her gray hair, Donata Grillo, a 75-year-old cancer survivor with a pacemaker and serious sight problems, sat next to her balcony, a damp sponge on her lap.

It was all she had to keep cool this week as temperatures topped nearly 106 degrees Fahrenheit, or 41 Celsius, in her native Rome. She does not own any air conditioning or fans, or even a functioning refrigerator, in her two-bedroom apartment in a public housing complex on the city’s periphery, next to...