Following a severe May heatwave, the World Health Organization (WHO) issued new global guidelines on Thursday in Berlin to accelerate climate adaptation and structurally overhaul health systems and urban spaces.

Over the past four years, extreme heat has claimed more than 200,000 lives across Europe, positioning it as the deadliest climate-related hazard. As new climate data reveals, global warming was pushed to 1.37°C above pre-industrial levels in 2025 – and is expected to breach the critical 1.5°C threshold within four years. WHO estimates the annual regional death toll could reach 120,000 by 2050 without effective intervention.

“Europe is warming faster than any other continent, and we are paying for it in lives,” said Dr Hans Henri Kluge, director of the WHO’s European Region (WHO/EURO), presenting the updated guidelines for Heat-Health Action Plans.

Rather than treating heatwaves as isolated emergencies, the updated WHO framework urges governments to fundamentally redesign their cities, workplaces and health systems. S

tructured around eight core elements – governance, warning systems, populations at risk, communication, resilience, reducing heat exposure, surveillance, and evaluation – the new approach shifts toward urgent, practical interventions that actively reduce thermal exposure across society.

Redesigning for cooler cities

Urban landscapes currently amplify extreme heat through dense infrastructure and heat-absorbing materials. “Large, densely built-up cities are particularly vulnerable to the dangers of summer heat,” noted Berlin Senator for Health Ina Czyborra at the launch.

To counter this, city planners are urged to embrace the “sponge-city” principle, replacing concrete with permeable surfaces, expanding tree canopies, and utilizing reflective materials to disperse accumulated heat. Beyond city limits, preserving natural ecosystems such as moors, forests, and floodplains provides a vital cooling buffer that actively retains water in the landscape for broader metropolitan areas.

“Nature can help us combat the heat if we let it,” emphasised German Federal Environment Minister Carsten Schneider.

Protecting workers and patients

As extreme temperatures drive patient surges and disrupt supply chains, the updated WHO guidelines urge health administrators to build structural resilience and implement robust heat-health surveillance to track real-time morbidity. This includes backup power for cooling systems, protecting temperature-sensitive medication, and safeguarding digital infrastructure from heat-induced failures.

Simultaneously, the framework mandates that employers implement strict occupational protections to shield frontline medical staff, construction workers, and agricultural labourers from severe heat stress. Employers face new directives to enforce mandatory acclimatisation periods, provide shaded rest areas, and adapt personal protective equipment.

Crucially, the guidance states that supervisors must establish clear communication channels that empower workers to halt unsafe labour and seek immediate medical help without fear of reprisal.

Ensuring equitable survival

Because extreme heat disproportionately targets the isolated, the elderly, and the economically disadvantaged, WHO insists that survival cannot depend on individual resources alone.

The new guidance mandates that local authorities formally map vulnerable populations and link this data directly to heat-health warning systems, ensuring that official alerts instantly trigger targeted outreach, including proactive home visits and wellness checks during thermal spikes.

The framework also calls for public health messaging campaigns to be co-designed with affected communities to guarantee inclusivity and cultural relevance. Consequently, health authorities are instructed to utilize diverse dissemination channels to ensure that life-saving advice reaches transient populations, undocumented migrants, and those lacking digital literacy.

The cost of resilience

While the guidelines provide a clear roadmap for adaptation, executing this transformation requires authorities to explicitly identify sustainable financing mechanisms and establish embedded monitoring, evaluation, and learning systems to track their effectiveness.

As European Commissioner for Climate Wopke Hoekstra noted in his foreword, “The evidence is clear: investing in emission reductions is far cheaper than paying for climate damage.”

Yet, this remains a profound challenge amid the ongoing war in Ukraine and strained European government budgets due to increased defence spending.

Addressing questions on expiring adaptation funds during the Berlin launch, Schneider acknowledged the “poor financial situation” currently complicating national budget negotiations.

With even a wealthy economy like Germany struggling to secure this funding, the pressing question arises: which states and cities will actually be able to facilitate the investments urgently needed to prevent deaths from extreme heat and yield those future returns.

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Image Credits: Luis Graterol via Unsplash, EU/Copernicus, Felix Sassmannshausen/HPW.