Europe’s Deadly Summer Exposes Urban Heat Vulnerability

Last summer, southern Europe experienced 23 tropical nights—when temperatures never drop below 20°C—nearly triple the historical average. The consequences were devastating: 24,400 people died from heat-related causes across 854 European cities between June and August.

“Europe is heating up, and we’re not prepared for the toll this will take on our health,” says Dr. Madeleine Thomson, Head of Climate Impacts & Adaptation at Wellcome. Thomson, who previously directed the WHO Collaborating Centre on Early Warning Systems for Climate Sensitive Diseases at Columbia University, warns that deaths represent only the most visible impact.

The majority of heat deaths occur quietly in homes and hospitals, where people with existing health conditions are pushed beyond their limits. Older adults are especially vulnerable—85% of last summer’s deaths occurred among people over 65. Children and pregnant women face heightened risks too.

Cities compound the problem through the “urban heat island effect.” Buildings, asphalt, and concrete trap heat, making urban areas significantly hotter than surrounding rural regions. When nighttime temperatures refuse to drop, bodies get no recovery period from daytime heat stress.

Solutions exist: adding green spaces and waterways to cool urban areas, implementing early warning systems, establishing cooling centers, and adjusting work schedules during peak heat. Cities are better prepared than during the 2003 heatwave that killed 70,000 people, but emergency services struggle to keep pace with rising temperatures and aging populations.

“If we don’t act now, the toll will rise,” Thomson emphasizes. “We must urgently phase out fossil fuels and implement policies that protect those most at risk from increasingly deadly heatwaves.”