The warning centers on babies' higher heat risk: NHS guidance says they should sleep in rooms at 16-20C, while one east London family said their five-month-old's bedroom reached 31.2C.
The groups said 1.59 million children overall are affected, with polling of 1,592 parents finding 70% said overheated homes disrupted children's sleep and 49% said it hurt concentration.
Housing leaders said England's homes were built for a cooler climate and urged better data, retrofitting, tougher overheating rules and funding, while the government pointed to new building standards and grants for air-to-air heat pumps.
As thousands of babies face heat risks, who will pay to make UK homes safe: residents, landlords, or the government?
Are external shutters and urban greening the overlooked keys to cooling Britain's dangerously hot homes?
The Hidden Danger in English Homes: Millions of Children Exposed to Extreme Heat and What Must Change
Overview
England is facing a growing public health crisis as homes become increasingly vulnerable to extreme heat. Heatwaves are now more common, with record temperatures reaching 40°C in 2022 and causing thousands of early deaths. The Met Office reports that the chance of such extreme heat has tripled since 2000, and future heatwaves could last a month or more. Without major changes, over 90% of UK homes could overheat by 2050, putting millions—especially children—at risk. This urgent situation highlights the need for better housing design, stronger policies, and immediate action to protect families from dangerous heat.