Sitting in a park in Zaragoza, a city in northeastern Spain, Jorge Jiménez, 41, was trying to enjoy a day off from his job as a municipal garbage collector. But the heat was making it difficult.
“We get very hot these days,” Mr. Jiménez said. “It’s horrendous.”
He was not alone.
Large areas of southern Europe baked under extreme temperatures on Thursday, the latest in a string of heat waves that have scorched the continent over the summer and sent residents and tourists scrambling for cool shelter.
In a region where it is not especially common for homes and businesses to have air-conditioning, many areas sweltered under temperatures exceeding 86 to 95 degrees Fahrenheit, or 30 to 35 degrees Celsius, and some topped 104 degrees. Temperatures in some cities were not as high but still far above the norm for so late in the summer.
In France, where the heat wave hit record highs after days of rising temperatures, construction workers and grape pickers started their days before sunrise. Many residents kept their shutters closed as they hunkered down in darkened homes or hunted for air-conditioned spaces like movie theaters.
In Italy, the Health Ministry has issued heat-related red alerts in more than half of the country’s 27 main cities, including Florence, Venice, Milan and Rome, where tourists crowded around water fountains and tried to keep the sun at bay with straw hats, bandannas and umbrellas.
And Spain is sweltering under its fourth heat wave this summer, even as firefighters battle blazes that have broken out in the country’s central and southern regions. One blood transfusion center in the city of Valladolid even made an urgent plea for donors to give blood because stocks were running low in the heat. “When it’s hot, people go out less, and they’re more afraid of adverse reactions such as fainting,” said Marta Yañez, a hematologist at the center.
Although it is difficult to link individual events to climate change, scientists say that it is fueling more extreme weather events, and heat waves in Europe have increased in frequency and intensity more quickly than practically anywhere else on the planet.
“We are beating temperature records every day,” Christophe Béchu, the French environment minister, told RTL radio on Thursday, “which shows how quickly climate imbalance is accelerating.”
France’s national weather forecaster said on Thursday that the heat wave was “durable and intense” in about two-thirds of the country, with “remarkable and even exceptional” temperatures in some areas, like the Rhône Valley and parts of the south.
Wednesday was the hottest day ever recorded in France since 1947 for the second half of August, with an average nationwide temperature of 81.5 degrees Fahrenheit, according to the French weather forecaster — breaking a record that had already been broken twice this week. Temperatures were expected to fall starting on Friday.
Not even northern regions along Spain’s Atlantic coast — where vacationers usually flock for cooler climes in the summer — have escaped the extreme heat. On Wednesday, Bilbao, a busy port city that is home to a Guggenheim museum, hit a stifling record temperature of 110.7 degrees Fahrenheit.
Officials in several countries have asked people to avoid strenuous activity outside and urged seniors and children to stay home and hydrated.
In the Drôme, an area of southeast France that has been hit particularly hard by the broiling temperatures, the local authorities have banned all nonaquatic sporting events until further notice and asked organizers to schedule any outdoor cultural festivities later in the day.
The authorities have also recommended that businesses shield their employees as best they can.
Mr. Jiménez, the garbage collector in Zaragoza, said that he and his colleagues were not allowed to push heavy collection trolleys or drive sweeper trucks not equipped with air-conditioning.
“It’s hell,” he said. “Even if you lower the windows, there’s no cool air.”
Since the death last summer of a garbage collector in Madrid who collapsed while sweeping streets, protocol also dictates 10-minute breaks in the shade every hour.
Some workers have taken matters into their own hands.
In Italy’s northern region of Veneto, about a hundred irate workers at a home appliance factory of Electrolux, a Swedish multinational, ended their shifts earlier on Wednesday because they felt that measures put in place to mitigate heat — including cooling systems and the provision of watermelons — were insufficient.
Many cities across southern Europe are trying to keep their citizens cool by extending park hours. In Lyon, France, the city authorities did the same with air-conditioned spaces like museums.
In Marseille, a Mediterranean port, officials said municipal pools would offer free access all week, even as France’s vast but aging public pool system feels the strains of rising energy costs, increasing water scarcity and struggling public budgets.
In Zaragoza, the City Council made a similar decision by offering a 40 percent discount on entry to municipal pools.
But Rocío Ramón, 40, a local resident and secondary school teacher, said the bus stop to get to the closest pool was a 10-minute walk — far too exhausting an endeavor in the intense heat. Ms. Ramón was playing in the early morning with her young daughter on the swings of a local park before it got too hot to stay outdoors.
“We just wish this was over,” she said.
Gaia Pianigiani contributed reporting from Rome.