Witnessed by the Citizen, around 100 vociferous students at
Denbigh School ignored teachers' orders to stay in school during the soaring heat and made a run for it out of the main entrance shortly before midday.
Furious teachers managed to round up most of the children – who were chanting 'we want half a day' – to return to class within five minutes of the break-out.
But small pockets of youngsters escaped towards the Shenley Church End shops and, despite a teacher's best efforts to search them out, did not return to school.
The Citizen was alerted to the incident by calls from several pupils angry that they had to remain in school while nearby Shenley Brook End School was closing early due to 'excessive heat'.
Ironically, one of the suspected instigators of the Denbigh protest was sent home half an hour later as his punishment. His mother, who was called by the school to pick him up, voiced her displeasure to the Citizen outside.
Headteacher Mrs Sarah Parker would not comment on the incident but a school spokeswoman said: "The kids are just getting a bit excited with all the media hype about the hot weather.
"We are in line with all the other MK schools in keeping the pupils in today, apart from one other school which I believe is off."
Some sixth formers at Denbigh were less than impressed with the protests of their younger school colleagues, who were mostly aged between 14 and 16. One told the Citizen: "They're behaving like silly little kids."
Meanwhile, Shenley Brook End School closed at 1.15pm yesterday. A spokeswoman for the school said shortly before the closure: "We are closing on health and safety grounds. Because modern schools are built with so much glass it gets like a hot-house.
"It was very uncomfortable this morning."
The Citizen understands that several other city schools asked if they could close but were advised against it by the LEA.
jon.boyle@mkcitizen.co.uk