More than 40,000 people died due to extreme heat in England between 1988 and 2025, according to Office for National Statistics figures, with deaths concentrated heavily in London, where 7,675 excess deaths occurred on the hottest days over the period. Experts have branded the toll a "national scandal", warning that heat deaths are on track to overtake cold-related deaths, undermining previous assumptions that milder UK winters would offset rising summer heat risks as the climate warms.

In 2025, the most recent year with data, 2,805 people died on the hottest days in England and Wales, exceeding the 2,244 deaths recorded on the coldest days for the first time in the four-decade dataset, though cold deaths have historically outnumbered heat deaths roughly three to one overall. The figures exclude this year's summer, during which the UK Health Security Agency estimates 2,877 people died in the May and June heatwaves alone. Extreme heat is particularly dangerous for the elderly and young children, raising the risk of heart attacks, strokes and complications from existing conditions, and in 2025 heat deaths outstripped cold deaths in every region of England and Wales except the north-west and south-east of England.