100 years ago all boys were required to wear shorts as part of the uniform during warm weather. It was, even then, considered a health risk & a deterrent to education during those hot & humid days for the kids to uncomfortably or dangerously overheat. The instructors can have an option of a fan under or near their desk or instructional area they work in, but the students don't have the option to "plug in" something that would help. Most aren't even allowed a spray or water bottle to splash their skin with in class.
It can get dangerously humid in the UK for kids in some of those schools in warm weather.
Golly. You'd think it would be better to give the kids the peak of the summer off, even if it meant starting school in Aug.
They'd sure save a lot on AC/ventilation costs.
Surrounded by ocean, with the gulf is stream pumping heat & thick humidity in mid-July, some parts of the UK can be as rough as living in a swamp in S.E. Asia this time of the year. It's gotta be rough on the kids in many of the schools with no or little AC, or poor ventilation.
Unlike a century ago when they designed buildings to be cooler in summers or closed them down in summers, modern buildings are not designed with lots of strategically located north or cool breeze facing windows & ventilation. 100 years ago if a building or space was too uncomfortable in winter or summer, it was abandoned when it was uncomfortable, or modified to make it better.