Rachida Belkacem keeps a folding chair beside the entrance of a public library in Barcelona's Ciutat Vella district, close enough to the automatic doors that she can feel the cool air spill onto the pavement outside. On the hottest afternoons this summer she has arrived by nine, before the library opens, joining a line of retirees, delivery workers on break and mothers with young children waiting for the doors to unlock. Inside, a sign in green and blue lettering marks the building as a "Refugi Climàtic," a climate shelter, part of a municipal network created to give residents somewhere to sit, rest and drink water when the temperature outside becomes dangerous.
The queue outside that library is a small, ordinary scene repeating itself across a continent this summer. Since late May, Europe has been gripped by a succession of record-breaking heatwaves, and the human toll has fallen hardest on those least able to escape it: the elderly living alone, outdoor laborers, people in poorly insulated apartments, and those without the means to run air conditioning even where it exists. What began as a meteorological story about broken temperature records has become, block by block, a story about how ordinary people are rearranging their days, their routines and sometimes their homes just to stay safe.
The scale of the heat has been unusual even by the standards of a warming continent. Researchers found that Europe endured five intense heatwaves between 1950 and 1999, but 18 between 2000 and 2021, and including the extreme heatwaves of 2022, 2023 and 2025, that figure has climbed past 20 severe heatwaves in just 25 years. This year's heat arrived earlier than usual. Since 1950, only one other major heatwave has struck Europe earlier in the year than this one, weeks before the traditional peak of summer in mid to late July. Temperature records have fallen across Belgium, France, Germany, Hungary, Romania, Ireland, Italy, the Netherlands, Poland, Czechia, Denmark, Spain and the United Kingdom since late May.
The human cost has been severe and geographically wide. The World Health Organization's director-general, Tedros Adhanom Ghebreyesus, reported that 1,300 excess deaths had occurred across Europe since June 21, and wrote that Europe is warming at twice the global average, with infrastructure not built to withstand the temperatures now recorded. In France alone, roughly 1,000 excess deaths, the number above what would normally be expected for the period, have been attributed to the heatwave. Some of the individual losses have been documented by name of place, if not always of person. In the Bordeaux region, three people between the ages of 80 and 95 died over a single weekend from health issues linked to the heat, according to local government official Sophie Brocas. In Carpentras, in southeastern France, a two-year-old and a four-year-old were found unconscious in a family car and could not be resuscitated, with local prosecutor Hélène Mourges saying investigators consider heat the leading line of inquiry.
Why does the heat kill so quietly, and so disproportionately among certain groups? Garyfallos Konstantinoudis, a lecturer at Imperial College London's Grantham Institute, explained that heatwaves cause heat stress when the body struggles to regulate its own temperature, which can progress to dehydration, heat exhaustion and, in severe cases, heatstroke, a medical emergency in which the body's core temperature climbs above 40 degrees Celsius and can no longer cool itself. The danger compounds for people already living with chronic illness, for infants and young children whose bodies regulate heat less efficiently, and for those who are simply alone. Researchers with World Weather Attribution note that vulnerability to heat spans elderly people living alone as well as populations facing socioeconomic disadvantage and chronic illness, including homeless people and migrants, a pattern that argues for adaptive, equity-focused heat-health policy rather than blanket warnings.
Cities have responded by trying to make relief physically reachable rather than merely advised. Barcelona's Climate Shelter Network, first launched in 2019, now includes more than 500 spaces, libraries, community centers, sports facilities, museums and green spaces, of which over 75 percent are indoor facilities kept at a comfortable temperature, with the remainder made up of parks, gardens, courtyards and some swimming pools. City officials say the shelters are open to everyone but are especially intended for the elderly, young children and people who struggle to keep their own homes at a safe temperature. This year the network has been extended into neighborhoods judged most vulnerable to heat, and municipal officials have gone further than posting maps. For the first time, the city has deployed street information officers in its most heat-vulnerable neighborhoods specifically to tell elderly residents where the nearest shelter can be found. First Deputy Mayor Laia Bonet framed the effort in blunt terms, saying the city is working to improve its local climate, with special attention to the most vulnerable neighborhoods.
Even well-designed shelter networks face real limits, researchers caution. A mobility-justice analysis of Barcelona's system found that reduced walking speeds among older adults and gaps in shelter opening hours can significantly narrow effective access for the people who need it most, while socioeconomic conditions such as low income and migrant status create overlapping layers of vulnerability that a map of shelter locations alone cannot solve. Air conditioning remains part of that same unevenness. Mechanical cooling can mean the difference between discomfort and medical crisis for older people, those with chronic disease, and residents of poorly ventilated apartments, yet air conditioning is not equally available and can be financially out of reach for people living in energy poverty.
Other cities and countries have improvised their own responses as the heat has spread eastward through the continent. In Paris and Denmark, initiatives to monitor the welfare of elderly residents individually have gained new momentum this summer. Health authorities across the region have repeated the same basic guidance: stay in air-conditioned spaces where possible, avoid direct sun during peak afternoon hours, drink fluids regularly, and check on elderly neighbors and relatives. In France, officials went further still, banning public drinking of alcohol in Paris as hospitals reported reaching breaking point under the strain of heat-related admissions, and postponing the city's Pride march to September after police ordered its cancellation.
The underlying trend, scientists say, is not a single unlucky summer but a shifting baseline. The World Health Organization's European Region is the fastest-warming of the six WHO regions globally, with temperatures rising at roughly twice the global average rate, and heat-related mortality across the region has risen by 30 percent over the past 20 years. Absent further adaptation, the organization projects that annual heat-related deaths across the region could rise from roughly 47,500 in 2023 to as many as 120,000 a year by 2050.
For now, the response remains local and daily, measured less in projections than in small, repeated acts of adjustment. Outside the library in Ciutat Vella, the doors open at ten. Belkacem folds her chair, gathers her bag and steps inside, into the cool air, to wait out the hours until the heat outside begins, however slightly, to break.
