'Silent killer' heatwave thought to have left at least 9 dead in Europe

At least nine people in Europe have died in savage heat this week as a "silent killer" heatwave continues to bake the continent.

In Italy, scorching temperatures of up to 38C forced officials to issue the most severe red alerts across 17 major cities, including Milan and Rome, while several regions banned outdoor work in the afternoon.

But the sweltering conditions - locked in by a 'heat dome' hovering over Europe - have already been implicated in the death of at least one labourer.

Local reports say Brahim Ait El Hajjam, 47, keeled over in the midday sun while pouring concrete in a car park on the outskirts of Bologna, which was also under a red alert.

Two men over 60 died on beaches in Sardinia, the ANSA news agency reported, and in Sicily's capital Palermo, a 53-year-old woman died on Monday after reportedly fainting while walking along a street. Local media said she had an existing heart condition.

The results of post-mortem examinations have not been published, but heatwaves kill thousands of people a year in Europe, earning them the nickname the "silent killer".

During the long, baking summer of 2022 in Europe, its hottest on record, 61,000 people died because of the heat, a study found.

The head of Italy's society for emergency medicine (SIMEU), Doctor Alessandro Riccardi, said A&E admissions have spiked in the current heatwave.

"We have observed a 10% increase in admissions compared to the national average, with some peaks (up to 20%) in Sardinia, which is among the regions most affected by the temperature at the moment," he told Sky News.

"More than absolute numbers, the composition of patients has changed, with an increase in patients requiring hospitalisation, and on this, the temperature plays a predominant role".

How does heat affect the body?

Heat sends the body into overdrive as it has to work harder to pump blood and keep itself cool.

The strain stresses the heart and kidneys and can lead to organ failure, heart attack and kidney failure - so heat stress often worsens existing cardiovascular and other problems.

Dr Akshay Deoras from Reading University said: "Heatwaves are deadly."

Prolonged heat exposure can "overwhelm the body's ability to regulate temperature, leading to dehydration, heat exhaustion, and potentially fatal heatstroke", he said.

It should be treated "with the same seriousness we give to dangerous storms", he added.

Power down and food burned

Temperatures in Italy are expected to remain in the high 30s into Friday, with the mercury likely to hit 39C in Florence today.

The heat was also blamed for power blackouts in central Florence and Bergamo, likely due to a surge in demand for energy driven by air conditioning. Farmers have complained of burned fruit and vegetables and a drop in milk production.

In Spain, fierce temperatures have soared even higher, reaching 46C in Huelva on Saturday and 37.9C in Barcelona yesterday, where officials are also investigating whether the death of a street sweeper at the weekend was heat-related.

Authorities also reported heatwave-linked deaths in Extremadura and Cordoba.

France's energy minister reported two deaths with a direct link to the heatwave, and 300 more taken to hospital.

Its capital could see 40C heat again today, and the top of the Eiffel Tower remains closed, as do hundreds of schools.

Meanwhile, in Germany, firefighters tackled several forest fires in the eastern states of Brandenburg and Saxony amid 40C (104F) temperatures in some areas.

Early heatwave a worry

What is worrying officials is that this heatwave began in June, whereas such high temperatures usually only come in July and August.

Samantha Burgess, strategic lead for climate at ECMWF, says: "The current June-July heatwave is exposing millions of Europeans to high heat stress."

She added: "Climate change is making heatwaves more frequent, more intense, and impacting larger geographical areas."

All this has come as the world has warmed by 1.3C on average since the pre-industrial era. It is on course to warm by about 3C by 2100.

High temperatures happened before humans changed the climate, but global warming is making them more common and more intense, turning mild weather hot, and heatwaves more dangerous than they would have been.

(c) Sky News 2025: 'Silent killer' heatwave thought to have left at least 9 dead in Europe