The nature charity WWF has called for more trees and natural surfaces to be brought into school playgrounds to help regulate soaring temperatures during heatwaves.

Schools are usually surrounded by open spaces, and over recent years these have increasingly been converted into artificial surfaces such as asphalt, astroturf and rubber crumb. These surfaces absorb much more heat than natural ones like grass, soil or sand, which in turn heats the air around the school.

In the record-breaking June heatwave, extreme heat forced hundreds of schools to close and many more to keep children indoors - 63% of primary school teachers, who responded to a recent poll, said they’d been forced to keep children indoors over break or lunch, while 97% said they had made changes to the way they use their outdoor space. Some reported classroom temperatures which exceeded 40 degrees.