Europe boils under deadly heatwave: What’s causing it, who’s suffering most and why it may get worse

People refreshes themselves at a fountain in Reims, northern France, on July 1, 2025 as a heatwave hits France.

This summer, Europe is facing lethal sweltering conditions that have pushed national records, strained critical infrastructure, and claimed lives across the continent. From Portugal to Poland, temperatures have soared well above 40 °C in numerous countries, triggering widespread alerts and emergency measures. As the world’s fastest-warming region, which is heating nearly twice as fast as the global average, Europe is becoming a frontline of the climate crisis, where each heatwave amplifies human suffering, economic disruption, and existential urgency.

Countries under siege

Southern European nations have borne the brunt of the heatwave. Spain, Portugal, France, Italy, Greece, and the Balkans have recorded temperatures beyond 40 °C, with Spain's Huelva region cresting 46 °C and Portugal setting new June records at 46.6 °C.

Daily excess deaths are alarming: the UK alone has seen an estimated 570 fatalities, with Spain reporting 114 and wider Europe tracking at least 684 confirmed heat-related deaths.

The World Health Organisation (WHO) estimates that extreme heat kills about 175,000 Europeans annually, and that number is climbing. Heatwaves in 2022 and 2023 together claimed over 130,000 lives, signalling a grim trend, and Europe saw record June mortality due to heat.

'Silent killer'

Tens of thousands of people have died in Europe during past heatwaves, prompting authorities to issue warnings for the old and young, the sick, and others vulnerable to what experts call a "silent killer".

On Tuesday, police in Spain said a two-year-old died in the country's northeast after being left in a car in the sun for several hours.

"Due to climate change caused by humans, extreme heat is becoming more frequent and intense. This is something we must learn to live with," said Clare Nullis, spokesperson for the World Meteorological Organization (WMO), a UN agency based in Geneva.

Extreme heat can cause dehydration, muscle cramps, headaches and nausea. The most serious risk is heatstroke, which can lead to death, especially in vulnerable people. Free guided tours of air-conditioned museums in Venice and free access to swimming pools in Rome were offered to protect seniors.

According to a report by Allianz Trade on Tuesday, the European economy could lose 0.5 percentage points of growth this year due to recent heatwaves.

The health impact will take longer to assess. According to France's Ministry of Health, an initial estimate of excess mortality during the period will be available approximately two weeks after the end of the heatwave, but detailed data based on medical data will not be available until the fall.

Emergency measures underway

Governments are scrambling to protect citizens. France and Italy have enacted bans on outdoor work during peak heat hours, closed schools, and shut iconic landmarks like the Eiffel Tower summit. In Germany, hospitals and care homes are pushing for better air conditioning and training to prepare for heatstroke emergencies.

Cities from Rome to Venice are offering free access to air-conditioned spaces, swimming pools, and public fountains. Emergency services are on standby, and wildfires have ignited evacuation efforts, including 50,000 people in Turkey’s Hatay region.

Infrastructure is also suffering: rail tracks, roads, and power grids are under stress, with EU-wide measures now being drafted to “stress-test” critical systems in heat scenarios.

Global agencies sound the alarm

World Meteorological Organisation (WMO) spokesperson Clare Nullis stressed that heatwaves will continue to intensify and become more common due to human-caused climate change. Dr Friederike Otto of Imperial College London affirmed that the current heatwave wouldn't exist without fossil-fuel-driven warming—calling it a climate signal borne from humanity’s emissions path.

The WHO cautions that heat waves are now a daily reality in Europe, calling for urgent adaptation strategies around health, urban planning, and public infrastructure. The European Environment Agency adds that extreme weather events, heatwaves included, have caused 85,000–145,000 fatalities across Europe in the past 40 years, with heat accounting for over 85% of those deaths.