Bradford weather this week pushed one school in Hertfordshire to more than 40C, according to Harry Paticas of Retrofit Action for Tomorrow. The heat has exposed how quickly classrooms, play spaces and school routines can tip into disruption when temperatures rise.
Harry Paticas said modern buildings often have too much glass and too little shading or ventilation to keep out the sun’s heat. He also cited work with 80 schools across England, where 68% reported overheating and more than a quarter described it as significant.
Hertfordshire school heat
The temperatures recorded in Hertfordshire were part of a wider surge in summer heat this week. Pupils and teachers have reported fainting or vomiting in class, while some schools have closed, exams have been cancelled and vital study time has been missed.
Paticas described some glass atriums in buildings from the early 2000s as like “walking into a Kew hothouse.” He said those spaces can trap heat in ways that were not a priority when the buildings were designed.
Victorian design and glazing
Many Victorian school buildings were built around passive cooling and cross ventilation. Tall sash windows could open at the top and bottom to let warm air out and draw cooler air in, while external shutters and awnings helped keep students comfortable during hot weather.
That approach has often changed. Some windows now have restrictors that stop them opening too far, or at all, because of student safety concerns, and large expanses of glazing can turn classrooms into hotspots. Single glazing lets up to 37% more heat into a building than double glazing.
Playgrounds and next pressures
Outside, tarmac-covered playgrounds without trees can act like giant outdoor radiators, and hard surfaces can reach up to 60C during heatwaves. Outdated heating systems and poorly insulated hot-water pipes can also send heat into classrooms.
The immediate practical issue for schools is whether quick fixes can lower temperatures fast enough to protect teaching and safeguarding. Schools will also have to deal with flooding, water scarcity and more frequent extreme weather events over the next decade, making heat control one part of a wider resilience problem.
