Separate polling of 1,592 parents, commissioned by the NHF, found seven in 10 said an overheated home disrupted their children's sleep, while almost half (49%) said it affected their children's ability to concentrate.

Smythe said England's housing stock was largely built for a cooler climate. "The challenge used to be keeping heat in," he explains. "Now it's about keeping heat out."

In the short term, he recommends measures such as keeping curtains and blinds closed during the day, staying hydrated and using reflective window film to reduce heat levels indoors.

Longer term, he said the UK needed a more strategic approach, including collecting better data, targeted retrofitting of existing homes and learning from hotter countries through measures such as external shutters and reflective exterior paint.

"Ultimately, we're looking for government funding to help deliver those measures," he added.

Gavin Smart, chief executive of the CIH, said: "The ambition shown in the government's Warm Homes Plan , externalis a necessary first step in the right direction, and we also need to think carefully about whether the 1.5 million homes we aim to build in this Parliament will cope with the hotter temperatures we will increasingly see in the future.

"CIH believes that we need to strengthen building regulations around overheating and start to consider policies that will support people with the energy costs of keeping cool during future heatwaves."

A government spokesperson said: "Babies and young children are more vulnerable to the effects of heat and guidance, external is available on how to help keep your home cool.

"New residential buildings must now be designed to minimise unwanted heat from the sun and to allow windows to be open when it is cooler outside than inside to remove excess heat.

"We are also extending the Boiler Upgrade Scheme grants for air-to-air heat pumps, which can cool as well as heat homes, so these low-cost options are more accessible."

Additional reporting by Jonathan Fagg from BBC England Data Unit

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