BERLIN – A new warning from the World Health Organization’s European regional office has underscored the deadly human cost of rising global temperatures, announcing Thursday that more than 200,000 people across the continent have died from heat-related causes over the past four years — and the vast majority of these fatalities could have been avoided.
As communities across the Northern Hemisphere brace for what could be another record-breaking summer of above-average temperatures, public health officials stress that extreme heat is far more than just an uncomfortable nuisance. Unregulated exposure to sustained high temperatures can trigger heat exhaustion, and progress to life-threatening heat stroke that requires immediate medical intervention.
Dr. Hans Kluge, regional director for WHO Europe, framed the escalating heat crisis as an immediate consequence of human-caused climate change in an official public statement. “The impacts of climate change are a clear and present danger, and its most immediate and lethal manifestation is extreme heat,” Kluge said. “Heatwaves are no longer freak weather anomalies. They are now a recurring crisis inflicting suffering, claiming lives and fracturing our health systems and infrastructure.”
The agency is pushing national governments and local public health institutions across Europe to roll out comprehensive heat action plans immediately. Recommended interventions range from opening free, accessible public cooling centers for at-risk communities to implementing mandatory heat safety policies for workplaces, including scheduled outdoor work breaks and flexible shift scheduling that keeps employees out of the dangerous midday sun. Kluge emphasized that the long-term public health goal is non-negotiable: “Our goal is clear and our ambition is bold: zero heat-related deaths.”
The WHO’s warning came on the same day that global meteorologists confirmed the development of a new El Niño event in the eastern Pacific Ocean. Characterized by unusual natural warming of Pacific surface waters, El Niño is already projected to strengthen to potentially historic levels through the Northern Hemisphere summer and fall. Climate scientists explain that this natural climate cycle will amplify the existing long-term warming driven by decades of fossil fuel emissions, creating a high risk of turbocharged extreme weather events across every continent.
To help people protect themselves from heat-related illness this summer, WHO has published a set of clear, evidence-based public safety guidelines:
First, limit exposure during the peak heat window. The hottest hours of most summer days typically fall between mid-morning and late afternoon, so officials advise staying indoors or in shaded areas during this window when possible. If outdoor work or travel is unavoidable, avoid strenuous activity and prioritize shaded rest stops. WHO also recommends spending at least two to three hours in a cool environment every day during heatwaves, and reminds the public to regularly check official local heat warning updates to stay informed of changing conditions.
Second, take proactive steps to cool indoor living spaces. During daytime hours, close all windows and cover exposed glass with blinds, curtains or external shutters to block hot incoming sunlight. Once temperatures drop after dark, open windows to let in cool evening air. For households with air conditioning, WHO recommends setting thermostats to 27 degrees Celsius (81 degrees Fahrenheit) and pairing cooling with a fan to boost comfort while reducing energy use. The agency also noted that low-income urban and rural communities are disproportionately impacted by extreme heat, as substandard housing and lack of access to affordable cooling technology leaves them far more exposed to dangerous indoor overheating.
Third, maintain hydration and dress appropriately for hot conditions. Public health officials advise drinking one cup of water per hour even if you do not feel thirsty, to avoid gradual dehydration that can lead to serious health complications. Regular cool showers or baths are an effective way to lower core body temperature, and when those are not available, wiping skin with a cool damp cloth or using a mist spray can provide relief. Clothing should be lightweight, loose-fitting and light-colored to reflect sunlight, and the same rule applies to bed linens for overnight cooling. Anyone heading outdoors should also wear a wide-brimmed hat, UV-protective sunglasses and high-SPF sunscreen to avoid additional sun-related health risks.
Finally, prioritize protection for the most vulnerable population groups. WHO repeatedly stresses that children and pets should never be left inside a parked vehicle, even for a few minutes: internal temperatures can spike to deadly levels in as little as 10 minutes under direct sun. For caregivers pushing baby strollers, covering the carriage with a thin wet cloth provides cooling shade, while dry cloth traps heat and raises internal temperatures to dangerous levels — adding a small portable fan can also improve airflow for infants. Regular check-ins are critical for at-risk groups including adults over 65, people living with disabilities, and those with preexisting heart, lung or kidney conditions, as well as people who live alone who may not have anyone to help them if they become ill from heat. Manual laborers and other outdoor workers are also at especially high risk when work schedules do not allow for heat-related adjustments.