What are the effects – including mental effects – of heat stress on the health of city dwellers?
They are very broad, ranging from mild complaints such as listlessness, irritability, anxiety, sleeplessness, headaches, dizziness and loss of concentration to edema, skin rash, heat cramp and worse: heatstroke and even death. Vulnerable groups are the elderly, young children and babies, people who are overweight or have a chronic illness such as diabetes, cardiovascular disorder, kidney disease or lung disease, people with a mental disability and the homeless. Those who are active in the heat, for example sportspeople and people working outdoors, are also vulnerable.
What links do you see between heat stress and other social problems in the city?
Heat is related to age and health, but also to the amount of greenery around us, the state of our homes, economic conditions and, very importantly, loneliness. There is also a link with energy: if people turn to air conditioning in large numbers, that will significantly affect energy demand. Moreover, air conditioning exacerbates heat stress in the city because the heat emitted makes the city even hotter. On top of that, heat also stimulates aggressive behaviour.
What spaces and buildings cause most heat stress? And what spaces actually counter it? Are there any surprising outliers, upwards or downwards? In other words, based on your expertise, what should an architect or urbanist pay more attention to when designing?
More hard materials means more heat. That is one of the reasons why the City of Rotterdam is working hard to make outdoor space greener, because that will cause the temperature, and especially the wind chill factor, to drop. For buildings, the best protection against heat turns out to be sunshades on the exterior; so for architects this is a very important design consideration. I’m also curious about the effect of white roofs, buildings and asphalt, which is the subject of research at TU Delft and other places. Whitewashing a roof can make a big difference in temperature, especially for people who live beneath a flat black roof – like me.
What tip do you want to give the Film & Architecture Studio participants in making their short film?
Focus primarily on the inhabitants of the city! They suffer from the heat – as do their pets. Look out for the way areas, buildings and behaviour are interrelated. People who are healthy, live in a green area and have money for sunshading and air conditioning suffer much less from heat than people with poor health who live on a street without greenery and in poorly maintained housing, and who do not have the money for sunshading, or who – as tenants – cannot get permission for it. Apart from all that, dealing with heat is a matter of self-care – knowing what to do and not do – and care for one another. It’s also interesting to see what we can learn about dealing with heat with all the cultures in Rotterdam.
And – last but not least, since we’re a film festival – do you have a film tip for anybody who wants to learn more about heat stress?
No idea! I don’t know if such a film exists. I love the film The Biggest Little Farm. If we all treated the earth in that way, tackling the problem at the source, then maybe we wouldn’t have a heat problem any more.
(photography Esther Wienese: Marieke Odekerken)