Palmela, PortugalBy the time flames destroyed his tool sheds and began inching toward his home, Matthieu Paley had already doused his land with water and hurriedly propped up one end of his doorless, mobile chicken coop so the birds could escape out the bottom.

Portugal residents are familiar with wildfires. But last Thursday, as a record-breaking heatwave began its march across Europe, parts of the country topped 116 degrees Fahrenheit, a July record. That helped ignite 170 fires in one day, blazes that broke out from the southern Algarve coast all the way to the country’s far north. Just outside Lisbon, the capital, flames rushed up the brushy slopes surrounding a historic castle in Palmela—a fire Paley watched from his yard as