At least 760,000 children in England and Wales missed lessons as more than 1,700 schools closed or finished earlyThe gruelling heatwave that hit the UK in June caused pupils to miss more than 15m hours of lesson time as soaring temperatures forced hundreds of schools to close, according to a study.The research found that at least 760,000 schoolchildren in England and Wales missed lessons owing to closures during the heatwave – one of five in the UK this summer – as temperatures inside some c