UN 
As southern Europe enters the hottest week of the summer, city health services from Athens to Madrid are deploying targeted heat response measures based on street-level data, aiming to prevent a repeat of last year’s urban mortality spikes. In Athens, the municipal health directorate issued a Tuesday midday warning focused on elderly residents in the Kolonos and Kallithea districts, where real-time temperature sensors showed 3°C higher surface readings than the city average.
The World Health Organization (WHO) has formally classified extreme heat as a public health crisis for the first time this June, citing over 12,000 heat-related deaths across Europe between May and August last year. National health ministries are now under pressure to move beyond broad advisories. Instead, the focus is on granular, neighborhood-level interventions, such as mobile cooling units and targeted SMS alerts for at-risk groups.
In Barcelona, the city council’s data partnership with the Universitat Autònoma has enabled rapid identification of ‘urban heat islands’—zones where night-time temperatures remain above 28°C. This week, public cooling shelters in these zones extended opening hours until 2am, responding to an influx of over 6,000 residents on Monday night alone.
Despite these advances, data transparency and accessibility remain uneven. In Istanbul, the municipal government has pledged to expand its sensor network by 40% by the end of 2026, but civil society groups warn that publicly available data is still limited to daily summaries, hindering community-led adaptation initiatives.
With the UN’s SDG 3 (Good Health and Well-being) and SDG 11 (Sustainable Cities and Communities) both at stake, the European Commission has announced €50 million in emergency funding this summer for local data infrastructure, prioritizing cities that can demonstrate measurable reductions in heat-related hospitalizations by December 2026.
Frequently Asked Questions
Why did the WHO classify extreme heat as a public health crisis in Europe?
The WHO classified extreme heat as a public health crisis in June after over 12,000 heat-related deaths occurred in Europe between May and August last year.
How are European cities using local data to respond to heatwaves?
Cities are using real-time, street-level temperature data to implement targeted interventions like focused heat warnings, extended cooling shelter hours, and SMS alerts for at-risk groups.
What measures did Athens and Barcelona take during recent heatwaves?
Athens issued targeted heat warnings for neighborhoods with higher temperatures, while Barcelona extended public cooling shelter hours until 2am after a surge in usage during a heatwave.
What is the European Commission doing to support cities facing extreme heat?
The European Commission announced €50 million in emergency funding for local data infrastructure, prioritizing cities that reduce heat-related hospitalizations by December 2026.
What challenges do cities like Istanbul face in heat response efforts?
Istanbul plans to expand its temperature sensor network by 40% by 2026, but public access to real-time data remains limited, hindering community adaptation efforts.
