Spain endured its hottest day of the year Saturday, with temperatures topping 45C, while authorities in Italy expanded the number of cities on red alert for health risks to 16, as a heatwave engulfed southern Europe.

The hottest temperature by late afternoon was recorded in Ecija, Seville, at 46.5C, shy of the country’s all-time record of 46.9 Celsius hit in Cordoba in July 2017.

Europe’s heat record came in Athens in 1977 at 48C.

In the southern Spanish province of Granada, where the mercury rose to 45.4C, few people ventured outside.

Those who did sought shade and stopped to take photos of public thermometers displaying the rocketing temperatures.

Ice cream parlours did a brisk trade, and some restaurants installed sprinklers to spray mists of water over sweating guests.

Miriam Garcia, a student, wished she had not stepped outside.

“It is very hot, we have to drink water and put on sun cream all the time, stopping to have a drink at a bar every so often,” she said. “It would be better to be at home than in the street, it’s so hot.”

Dominic Roye, a climate scientist at the University of Santiago de Compostela, said hot air from the Sahara Desert that has brought days of heat and fuelled hundreds of wildfires across Mediterranean countries shows no signs of ending any time soon.

“The heatwave we are experiencing now is very extreme and a lot of people are saying that it’s normal, as we are in summer. But it’s not, not this hot,” Mr Roye said.

With night-time temperatures forecast to exceed 25C in much of Spain, Roye worried about residents who cannot afford air conditioning and other vulnerable people, like the homeless or outdoor workers.

“The more intense the heat, the higher the mortality risk,” he said.

“When you have high night temperatures, our bodies are prevented from resting.

“The body is working and working to cool down. We have found a strong link between mortality and night temperatures exceeding 20C.”

Authorities in Italy also raised concerns about older adults and other people at risk as they expanded heat warnings to 16 cities.

Temperatures in the mid-40s Celsius were forecast for the Sicilian cities of Palermo and Catania, and as high as 37C for Rome, Florence and Bologna, all places that the health ministry put on red alert.

Italians sought respite at the sea and in the mountains from the aptly named Lucifer anti-cyclone that was bringing hot air from Africa during Italy’s peak summer holiday weekend.

High temperatures were forecast to continue through Sunday, the traditional Ferragosto holiday on the religious feast of the Assumption of Mary, which marks the summer holiday exodus from Italian cities.

In Rome, drinking fountains provided relief, while authorities kept tourists away from ornamental fountains like the famed Trevi Fountain, fearing imitators of Anita Ekberg’s soaking in the film La Dolce Vita.

“I put my head under the water at each fountain, drinking a lot, staying in the shade as much as I can,” said Alessia Pagani, who was visiting from the northern city of Brescia.

High humidity accompanied the high temperatures, making it feel even hotter. Storms in the north were forecast to bring the first signs of relief starting on Monday.

“More than anything else, fresh air from the Atlantic will bring a coolness and greater ventilation that will sweep away the humidity and make the air much more breathable,’’ Lt Col Filippo Petrucci of the Italian air force’s weather service told RAI state TV.