European hospitals are failing to cope with extreme heat, with health systems across the continent buckling under temperatures that cause equipment failures, overwhelm cooling infrastructure and push patients and staff into dangerous conditions. Heatwaves are the leading cause of climate-related death in the World Health Organization European Region, which estimates 175,000 heat-related deaths annually. In 2023 alone, nearly 48,000 such deaths were recorded across Europe. During last month’s record-breaking heatwave, France raised its health system to the highest level of emergency mobilisation, while hospitals in Italy, Spain and Germany reported surging admissions and cooling systems that could not keep pace. The European Federation of Nurses Associations (EFN) has endorsed the #HandleTheHeat campaign run by Health Care Without Harm Europe, with nurses across the continent warning that responding to extreme heat requires more than emergency measures once temperatures soar.
Widespread infrastructure vulnerabilities
Nearly half of hospitals in European cities sit in urban heat island hotspots — areas at least 2°C warmer than the regional average due to the concentration of buildings and asphalt. This effect compounds the impact of heatwaves on urban healthcare settings, where ageing infrastructure and inadequate cooling leave facilities exposed. In Portugal, daily hospital admissions rose by 19% during heatwave days between 2000 and 2018, illustrating the additional burden placed on already stretched systems. Health professionals across Europe have signed an open letter to the European Commission demanding an EU climate and health strategy, stronger workforce protections, and support for low-carbon, climate-resilient healthcare facilities. The World Health Organization has released updated guidance on Heat-Health Action Plans, urging countries to anticipate, prepare for and respond to extreme heat through integrated preparedness, warning systems and cross-sector response mechanisms.
UK hospitals declare critical incidents
In England, the recent heatwave triggered a cascade of failures. Several NHS hospitals declared critical incidents as essential equipment and IT systems malfunctioned directly because of overheating. Radiotherapy machines, MRI scanners and kidney dialysis machines failed or became unusable when their cooling systems were defeated by high temperatures and humidity. In one case, a hospital reported having no working MRI scanners across its sites. At Guy’s and St Thomas’ NHS Foundation Trust in July 2022, IT systems failed due to extreme temperatures, sparking a critical incident that disrupted clinical services for weeks. Cooling units (chillers) broke down, causing elevated temperatures across entire hospital sites and affecting digital systems, operating theatres and diagnostic scanners. Many wards lack adequate air conditioning; indoor temperatures have reached 35°C, making conditions “awful” for patients and staff, who report working sleep-deprived and struggling to cope. Even wards with built-in air conditioning have been affected when units were shut down to prevent damage. Planned care, outpatient appointments and surgeries have been cancelled. Older patients present with dehydration and collapse, and staff describe conditions as “unsafe and dangerous,” with infection control becoming “almost impossible” in sweltering, cramped spaces.
The scale of the problem is systemic. Around 90% of NHS buildings in England are vulnerable to overheating. Indoor temperatures in some wards can exceed 30°C even when outdoor temperatures are around 22°C. Overheating incidents in NHS Trust buildings nearly doubled from 2,980 in 2016-17 to 5,554 in 2021-22. A 2024 survey of more than 1,000 UK healthcare professionals found that over 90% reported their performance was impaired by heat stress, and nearly three-quarters considered existing protections inadequate. The NHS is not only a victim of extreme heat but also a contributor: it is the UK’s largest public-sector source of carbon emissions, creating what the Office of Health Economics describes as a “vicious loop” — worsening health drives greater demand for care, which in turn increases emissions and fuels further climate change.
Policy responses lag behind
The NHS has a legally binding commitment to reach net zero by 2040 for direct emissions and 2045 for influenced emissions, and its Net Zero Strategy aims to build resilience and adaptation into operations. Yet the NHS 10‑year plan, which sets out a vision for transforming healthcare delivery in England, contains no specific proposals that explicitly address how to decrease NHS carbon emissions or how the plan interacts with the NHS’s fourth health and climate adaptation report. Nadine Henderson, principal economist at the Office of Health Economics, warns that there is an overwhelming risk that much-needed decarbonisation and adaptation activities are deprioritised amid competing reforms and scarce resources. The UK Health Alliance on Climate Change has urged governments to strengthen the health system’s resilience to rising temperatures, warning that adaptation efforts have lagged behind. The European Commission’s European Green Deal promotes resource efficiency and waste reduction in healthcare, and Horizon Europe funds research into environmentally sustainable, climate-neutral health and care systems. At the urban level, some European cities are implementing measures to mitigate the urban heat island effect — increasing green spaces and water features. But as Mark Wilson, executive director of Health Care Without Harm Europe, and Dr Paul De Raeve, secretary general of the EFN, argue: “Extreme heat is not an exceptional event and Europe’s response to it should stop being exceptional too. Protecting patients and those who care for them must become a core part of climate adaptation policy, not an afterthought.”
