Europe is the fastest-warming continent on earth, with temperatures rising at around twice the global average rate. Climbing temperatures can rapidly increase illness and deaths and place sudden pressure on essential services, such as health and social care. Extreme heat is a growing public health threat and health security challenge that is expected to hit harder each year. This summer’s toll is still being counted but, already, data from just 5 countries shows nearly 10 000 excess deaths due to heat.
WHO/Europe has developed a range of tools and public health advice to help countries prepare for and respond and adapt to extreme heat, which it recognizes as a recurring crisis in the WHO European Region. This includes a technical guidance and resource package for Member States on heatwaves and wildfires for the 2026 season.
Building resilient health facilities
Heatwaves can cause an influx of health-care admissions, putting pressure on facilities that may be ill-designed to cope with higher temperatures. Many city hospitals are impacted by urban heat island effects, with built-up areas significantly warmer than surrounding rural or suburban areas. This can cause buildings to overheat and lead to failures in power supplies, cooling systems and IT services, underscoring the need for strengthening the climate resilience of health facilities. Staff as well as patients are vulnerable to heat and increased temperatures, leading to stress and burnout.
In Romania, some hospitals are adapting to cope better with extreme heat. Buhuși Hospital is crucial for local people in hot weather. A designated cool space welcomes anyone suffering from heat stroke. Cool water is also made available, with medical staff trained to spot the early signs of heat exhaustion. In preparation for rising temperatures, the hospital has applied for funding to install a high-efficiency cooling system for the whole building.
Across the wider Region, WHO is helping hospitals to prepare for heat as one of a number of hazards through its Hospital Safety Initiative. This initiative relies on a standardized assessment tool called the Hospital Safety Index (HSI), which evaluates the likelihood that a hospital will remain operational during emergencies. While traditionally used to assess preparedness for natural hazards, such as earthquakes or floods, the HSI is increasingly supporting countries to identify climate- and weather-related hazards and vulnerabilities, such as extreme temperatures, including risks to power supplies, cooling systems, water availability and the well-being of patients and staff.
In recent years, countries, including Armenia, Georgia, Kazakhstan, Poland and Ukraine, have conducted HSI assessments and training programmes with WHO support, helping authorities to identify priority investments and strengthen preparedness. By integrating climate-related risks into hospital safety planning, the HSI helps ensure that health facilities can continue delivering essential services during heatwaves and other climate-driven emergencies.
An example from the United Kingdom of Great Britain and Northern Ireland
Heat–Health Action Plans (HHAPs) are used nationally and locally to bring together measures across the areas of preparedness, risk communication and response. Since WHO/Europe published the first comprehensive guidance on HHAPs in 2008, countries across the Region and globally have drawn on WHO advice to develop and improve their HHAPs, translating evidence into practical systems.
The UK Health Security Agency maintains an Adverse Weather and Health Plan, which sets out how the country prepares for and responds to weather-related health risks, including extreme heat. It uses a colour-coded alert system, developed with the country’s Met Office, and links each alert level to practical actions for health services, local authorities, community groups and the public, helping protect those most at risk and reduce pressure on the National Health Service during hot spells.
In anticipation of temperatures that soared up to a record-breaking 35.1°C in May 2026, United Kingdom officials issued amber health alerts, signalling potential health impacts across the wider population. Red alerts were issued in June 2026, when parts of the country reached unprecedented temperatures of up to 37.7°C. This unusually hot weather has underlined how HHAPs are vital in communicating the severity of high temperatures and the need to act accordingly. Since much of the country’s built infrastructure is not designed for hot weather, long-term adaptation is also vital.
New HHAP guidance
The WHO European Centre for Environment, Climate Change and Health in Bonn, Germany, has published new Heat–Health Action Plan guidance, providing an international point of reference for systematic, evidence-based health action. Not only will it support countries and local authorities in developing an HHAP for the first time – it will also help in the review, improvement and strengthening of existing HHAPs across the Region and globally. Its framework of 8 core elements highlights key actions and decision points for planning, coordination, delivery and continuous improvement.
As part of the new guidance, 5 user action briefs have been produced for different sectors alongside a public health message bank for risk communication, full of simple, practical steps people can take to protect themselves in hot weather – and to help those around them. At the heart of the guidance is the recognition that people are not passive recipients of warnings and advice. With the right information, support and practical actions, they can play an active role in protecting their own health and helping others stay safe during extreme heat.
The action briefs provide tailored recommendations for different population groups, ensuring heat-health messages are clear, accessible and actionable. They place a strong emphasis on reaching vulnerable and hard-to-reach communities, while identifying the most effective digital, traditional and community-based channels to maximize the impact of public health messaging. Drawing on WHO case studies and international best practices, the briefs support evidence- and insight-informed communication approaches that help people better understand, prepare for and protect themselves during extreme heat.
Action to mitigate the effects of a warmer planet
Increased heat in Europe cannot be solved by action in Europe alone; it is a global issue, requiring a coordinated, global response. In July 2024, United Nations (UN) Secretary-General António Guterres encouraged all countries to produce HHAPs and called for an urgent and concerted effort to enhance international cooperation to address extreme heat, bringing together 10 specialized UN entities, including WHO.
Within WHO’s Second European Programme of Work 2026–2030 (EPW2), driving climate health action and protecting populations from environmental risk is a key priority that is closely tied to maximizing health security. This includes heat action and HHAPs. Climate risks are also embedded directly into the Region’s core readiness objectives as part of Preparedness 2.0, WHO’s 5-year regional strategy (2024–2029) designed to strengthen health emergency preparedness, response and resilience across the Region. Its all-hazard approach is helping to close gaps in health security and strengthen collective readiness for future threats, such as the increasing frequency and intensity of extreme weather events due to climate change.
Even though the task of dealing with heat-related incidents is immense, if action is taken now, there is hope, as Dr Hans Henri P. Kluge, WHO Regional Director for Europe emphasizes, “Our Region is the fastest-warming region globally. In the past 4 years alone, heat has claimed more than 200 000 lives, while heat-related mortality has risen by 30% over the past 20 years. But heat deaths are not inevitable. We know how to protect people: warn communities early, make cities cooler, ensure access to water and shade, check on those most at risk and prepare health systems before temperatures peak.”
