Taking Care of Children During Heat Waves: What Can Schools Do?

In general, schools are the only public buildings that are not equipped and adapted for optimal thermal comfort. There is an urgent need to plan and invest resources in effective and sustainable measures to mitigate the effects of heat waves in schools, where children grow, learn, play and where teachers work.

[This text is adapted from an article published on the FAROS project website.]

It is no longer a surprise that climate change is increasing average temperatures and causing more frequent, intense and earlier heat waves. What is surprising and worrying is that, despite forecasts and estimates warning of worsening environmental conditions and their serious health impacts, we still seem to be caught off guard when they arrive.

In 2022, the period from May to November was accompanied by intense heat, with extreme heat episodes in July exceeding 26.6°C (the hottest ever recorded in Spain). Around 5,000 deaths in Spain were recorded as a result of these episodes, five times more than in 2018 or 2020. In addition to being a consequence of climate change, heatwaves are an urgent and important public health issue. Heat has many significant impacts on the health and well-being of populations, especially the most vulnerable, such as children and the elderly.

Photo: Mariona Gil / Barcelona City Council.

Boys and girls more vulnerable to heat

Children are more susceptible to dehydration, heat exhaustion and heat stress for several reasons related to the development of the thermoregulatory system and physiological capacities. On the one hand, children's sweating and vasodilation mechanisms are not as efficient as those of adults, they have a larger surface area exposed to the environment relative to their body mass, and they are less able to regulate their hydration.

In addition, they may have difficulty recognising and communicating that they feel hot and tend to be in constant movement, and this physical activity causes them to generate more internal heat.

When it's hot at school

Children and teachers spend much of their day in classrooms and playgrounds that are not prepared or adapted for the current and expected rise in temperatures. Having to learn, play and work in extreme and prolonged temperatures is a health concern. In addition to dehydration, heat stroke or heat exhaustion, children with asthma or other respiratory conditions can have their worse symptoms during heat waves. Stress caused by high temperatures can also lead to irritability, fatigue and general malaise, which can affect mood and behaviour in school and social activities.

Photo of a schoolyard in Barcelona before and after work to transformation into a Climate Shelter.

Extreme heat in classrooms can affect cognitive development

Extreme heat in classrooms can affect children's cognitive development by impairing concentration and focus, the ability to process and retain information, and overall performance. Studies suggest that high temperatures during the hottest part of the day can affect working memory, decision-making and performance on complex tasks.

Less attention has been paid to the impact that thermal comfort can have on teachers. However, a recent study by ISGlobal found that teachers' negative perceptions of indoor environmental quality could be associated with lower productivity, as reflected by symptoms that affect daily tasks and performance and longer periods of sick leave.

Schools, inadequately equipped and poorly adapted public buildings

With the increase in extreme heat events, schools are among the most important places to ensure children's health, well-being, development and effective learning. They should also provide healthy and safe working conditions for teachers. In general, schools are the only public buildings that are not equipped and adapted for optimal thermal comfort. Many are old and poorly insulated. They were built at a time when they would be empty during hotter months, facing south for light and warmth in winter. In the past, schools were only open during two of the hottest months, but in recent years this period has become longer and schools calendars have changed.

Photo: Barcelona City Council.

How schools can adapt to climate change

Schools must adapt to climate change. Greening schools can help combat the effects of heatwaves in a number of ways:

• Incorporating vegetation and permeable soil can help maintain cooler temperatures.
• Creating green spaces and using vegetation can provide shade and reduce ambient temperatures by acting as natural barriers to overheating and providing cool places. They also encourage physical activity and outdoor learning, restoring a connection with nature.
• Naturalised spaces in schools create a calm and relaxed environment that is conducive to learning and helps to reduce stress associated with extreme temperatures.
• Vegetation also helps to filter and purify the air, improving the quality of the air in the school environment. This is particularly important during heat waves when air pollution can be at its highest.

On the other hand, there is a need for good climatization in buildings. Effective and sustainable solutions can be implemented, such as

• Insulating the building.
• Using natural cross-ventilation or mechanical ventilation systems (ceiling fans).
• Installing blinds or curtains to block direct sunlight.
• Using reflective paint on the roof and dark surfaces.

It is essential to ensure good air circulation in classrooms to ensure good indoor environmental quality and thermal comfort. As we saw during the COVID-19 pandemic, good ventilation also has other health and well-being benefits.

Barcelona turns eleven schools into climate shelters

The city of Barcelona is implementing several measures to improve the school environment. Between 2018 and 2020, it transformed 11 primary schools into climate shelters to improve thermal comfort and create healthier, more playful and inclusive schoolyards and to mitigate the effects of climate change. This pilot project: Adapting schools to climate change through green, blue and grey, was funded by the European Commission. It implemented vegetation, water and shade elements in the playground and shading and natural ventilation elements in the buildings. The results of the impact assessment carried out by ISGlobal showed that benefits were achieved beyond improving temperature and thermal comfort, especially outdoors. The most highly rated solutions were the shaded areas and the incorporation of greenery. There are now more places to cool off on hot days, shaded and seating areas have been improved and courtyards have been made more natural and cooler. There is also more variety in the play areas, which encourages more egalitarian relationships among students.

Adjusting timetables to avoid the hottest hours, planning alternative indoor activities, avoiding the sunniest parts of the school or suspending classes during periods of extreme heat can help protect health, reduce discomfort and provide respite for the school community as an emergency measure, but should not be the norm. There is an urgent need to plan and invest resources in effective and sustainable measures to mitigate the effects of heatwaves in schools, where children grow, learn, play and where teachers work. A radical and immediate shift is needed to understand that climate action in our environment includes action for health and well-being.