The number of UK homes overheating in summer has quadrupled to 80% over the past decade, according to a study published in the journal Energy Research & Social Science. Researchers described the situation as a crisis, warning that heat already kills thousands of people each year in the UK and the toll will rise as the climate crisis intensifies.
The study, led by Dr Mehri Khosravi at the University of East London, compared survey data from 2011 and 2022. In 2011, 18% of households reported uncomfortable warmth in one or more rooms during summer, but by 2022 this had jumped to 80%. More than a third of households said their homes overheated daily, and a further 19% reported this happening five or six days a week.
The use of air conditioning soared sevenfold to 21% of homes between 2011 and 2022. Researchers warned that continued reliance on air conditioning could strain the national electricity grid, increase carbon emissions, and worsen social disadvantage for families unable to afford it. Half of respondents said they had little or no knowledge of how to cope with extreme heat.
Heatwave deaths are often hidden, with many attributed to heart attacks, strokes, and respiratory or kidney problems exacerbated by high temperatures. Data from the UK Health Security Agency shows more than 10,000 people died as a result of summer heatwaves between 2020 and 2024. Bob Ward, chair of the London Climate Ready Partnership, said successive governments have failed to treat the issue seriously, leading to a crisis.
Overheating was highest in London, the south-east and the north-west, and lowest in the north-east, Wales and Scotland. Lower-income households were more than twice as likely to report overheating as high-income ones. Modern homes built after 1900 and those with high energy efficiency ratings were also more prone to overheating, due to airtightness and insulation that can trap heat without good ventilation.
