The Netherlands activated a national heatwave plan as temperatures reached 40°C pressure across the country, and Amsterdam households were told to hang curtains or sheets outside their windows. The advice aimed at keeping sunlight off large panes came as heat once again pushed the issue of indoor overheating into daily life.
Eline Coolen, the city’s heat coordinator at its public health institute, urged residents last week to rig up temporary curtain rails or drape fabric outside. She said, “In Dutch houses, but also in many houses in northern Europe, you have very big windows” and “We have always built for the winter, when you want as much sun and warmth in your house as possible.”
Amsterdam and the heat plan
Werner Hagens, the coordinator of the Dutch heatwave plan, said the response is built around three levels of action: behaviour, housing and urban design. He said, “You can make changes in the area, more green spaces, you can make changes in the building, like screens and maybe other cooling mechanisms, but you can also give perspectives on how people inside them can minimise heat.”
Hagens added, “These temperatures can form a risk for people in vulnerable health … and it reduces the risks.” The guidance gives households a direct action: block sun before it reaches the glass, rather than trying to cool already heated rooms later in the day.
Windows, heat and older residents
Eline Coolen said the scale of the problem is already visible in Amsterdam. “But every year in Amsterdam alone, 110 people die because of the heat – and that could rise to as many as 600 in the future without serious measures,” she said. The city’s advice singled out older and vulnerable people, the groups most likely to spend long periods indoors when temperatures climb.
Bert Blocken, professor of mechanical engineering at Heriot-Watt University, said the building stock itself is part of the problem. “Most of the time we spend indoors, even on very beautiful, sunny days, because we’re working or we’re sleeping, when we also recover from heatwaves,” he said. He added, “We need to keep our buildings cool, ideally without active cooling devices. The climate adaptation of individual buildings is important but still today, many are built with large, glazed facades that generate a lot of heat.”
Households in Amsterdam
A study by Vereniging Eigen Huis found that 23% of people surveyed felt their homes were too hot in a heatwave, while four in five said they had already tried to cool them down. That lines up with the city’s message: many households can act immediately, but the long-term problem sits in the way homes were built for damp, cold weather rather than hotter summers.
Blocken said, “If I were mayor, my first executive order would be to apply exterior solar shading on all buildings.” For households in Amsterdam, the immediate step is simpler than that: curtains, sheets or another exterior barrier that keeps the sun out before indoor heat builds. Officials and researchers are continuing to push those cooling measures, but the bigger shift still points toward housing and urban design changes that have not yet been set out in full.
