How cities can stay cool in the heat

Climate change is affecting us all – and in summer, we can really feel it. The problem is particularly acute in cities, where the heat interferes with our daily lives and often becomes a health risk. Record temperatures are becoming the norm, tropical nights are keeping us awake, and heatwaves are claiming thousands of lives.

Dr. Julia Schoierer works at the Institute and Polyclinic for Occupational, Social, and Environmental Medicine at LMU University Hospital, researching how the climate crisis affects our health. She co-developed Hitze Service (Heat Service) – an online portal that helps municipalities prepare for heatwaves and adapt to the consequences of climate change.

Adjusting our daily rhythm

“Our circulation has to cool our body down on hot days – and this consumes energy,” explains the expert in health education at LMU. “The midday and afternoon hours in particular are not the time for strenuous physical or mental activity,” she observes. Mediterranean cultures have long been aware of this – in Germany, it is something we will have to learn.

Schools should be flexible – having lessons outside in the yard, for example, or handing out damp facecloths when the classroom gets too stifling. Employers can make it easier for staff by facilitating flexible working hours, creating cool rooms, deferring strenuous and stressful tasks, and shutting down operations for a while when temperatures become extreme. This also prevents accidents and conflict, as heat clouds our minds and increases aggression.

»The midday and afternoon hours in particular are not the time for strenuous physical or mental activity.«

Julia Schoierer

Admittedly, such measures are not always possible. Police officers, care workers, and fire fighters cannot just stop working when the heat is extreme. In fact, that is when they are most needed. For people who work in these public roles, we need to find other solutions – things like increased staffing ratios and shorter shifts.

Water cools the body – and urban areas

In times of climate change, water becomes a valuable resource: “Water is wonderful for combating heat,” notes Schoierer. Because we lose a lot of fluid when we sweat, it is vital to drink enough water. Otherwise, we risk dehydration, heatstroke, and kidney problems. Cities can protect their populations by providing access to free drinking water – for example, by installing public drinking water fountains.

»Water is wonderful for combating heat.«

Julia Schoierer

“Water not only cools our bodies, but also entire urban districts,” says Schoierer. “A river, stream, lake, or even just a fountain are all boons for a city’s climate and a refreshing oasis for inhabitants.” Municipal authorities can address this issue and adapt cities to changing conditions through active urban planning.

When it is hot outside, it is important to regularly stop in cool places – under trees, beside rivers or lakes, or in places offering artificial shade. Cities become more livable and safer when they create and expand such refuges – by installing shaded benches on public streets, say, or putting roofs on bus stops and waiting areas.

Cool spaces – outside and indoors

“With clever urban planning, we can improve the overall climate in cities,” says the expert. By exploiting fresh air corridors, for example, cool air can be directed into downtown areas from the surrounding land and carry away the heat stored by buildings and infrastructure. Large green areas like meadows, fields, wasteland, horticultural land, and forests all function as such cold air generators.

In general, urban green spaces provide cooling, so cities should embrace measures such as greening façades and roofs, planting trees, and expanding parks. Paved-over surfaces, by contrast, are poison for the urban climate. As Schoierer explains: “Asphalt and paving stones store heat. Wherever possible, we should remove this surfacing from our cities.”

»With clever urban planning, we can improve the overall climate in cities.«

Julia Schoierer

Buildings should be designed and equipped in a clever way to ensure they do not overheat in summer. This applies not only to residential buildings, but also to schools, hospitals, nursing homes, offices, and government buildings. Using the right building materials, climate-friendly cooling systems, and suitable insulation can make a big difference.

Warning and protecting at-risk groups

All the tricks in the world will count for nothing if nobody knows them. By rolling out accessible information campaigns, info portals, and handy maps, cities can help their inhabitants by showing them where the city is most oppressive in heat, where the cooler spaces are, and where the public drinking fountains and toilets are located. They can warn people when a heatwave is coming and tell them what to do on hot days. What is important here is to present the information in a way that everybody can understand – no matter how old they are or what language they speak.

Personnel who deal with heat or its consequences – the likes of carers, teachers, and managers of sports facilities – must receive special training. Some groups are particularly at risk: the elderly and infants, people with acute or chronic illnesses, and pregnant women and their unborn children. Also, employees whose jobs require them to work in places exposed to the heat. Neither should we forget those who do not have a roof over their heads. Homeless people are especially vulnerable, as they spend most of their time outdoors and do not have any reliable shelter from the ravages of the sun.

So there are ways for municipalities to better deal with heat. If cities take these measures seriously and implement them, they can protect their populations during extreme weather events and save lives. This will become increasingly important in the future – as summers are getting hotter.

More hot topics in this issue:

• Scorching asphalt – the climate crisis in cities: Heat islands, heatwaves, record temperatures: How climate change is heating up Europe’s cities – and where it is hitting hardest. Read now!
• 10 creatures that defy heat: From hydrothermal vents on the ocean floor to the deserts on all five continents: We present ten organisms and their tactics for dealing with heat. Read now!
• Raging hormones: Nine million women in Germany are currently menopausal – and a third of them suffer from unpredictable hot flashes. Hormone expert Nina Rogenhofer explores how we can helf them. Read now!