Researchers estimate more than 2,700 deaths linked to England and Wales heatwaves

Researchers estimate that more than 2,700 people died from heat-related causes during the record-breaking heatwaves that affected England and Wales in May and June 2026, highlighting the growing impact of extreme temperatures on public health.

The study was carried out by researchers from Imperial College London, the Met Office and the London School of Hygiene & Tropical Medicine (LSHTM). Using weather observations, climate modelling and established methods for estimating excess mortality during periods of extreme heat, the team estimated that approximately 2,736 excess deathsoccurred during the two heatwaves.

Researchers estimate that around 550 deaths occurred during the May heatwave, when temperatures reached a record 35.1°C, while a further 2,200 deaths were associated with the more intense June heatwave, when temperatures exceeded 37°C in parts of England and the UK experienced rare red heat warnings.

The research found that older adults, particularly those aged 65 years and above, accounted for the majority of estimated heat-related deaths. People living with cardiovascular disease, respiratory illness and other long-term health conditions were also identified as being at greater risk during periods of prolonged high temperatures.

The researchers also estimated that approximately 42% of the deaths were linked to the additional heat associated with human-induced climate change, which increased temperatures during the two heatwaves.

Dr Mark McCarthy, Science Manager for Climate Attribution at the Met Office, described the events as “exceptional”, noting that the combination of extreme daytime temperatures, unusually warm nights and high humidity placed additional pressure on infrastructure, health services and vulnerable populations.

Heat-related deaths often occur indirectly, with high temperatures increasing the risk of heart attacks, strokes, respiratory complications and dehydration rather than heatstroke alone. This means the true health impact of extreme heat can be less visible than other weather-related emergencies.

The findings reinforce guidance from the UK Health Security Agency, which advises health and care providers to take additional precautions during periods of extreme heat. Recommended measures include encouraging hydration, keeping indoor environments as cool as possible, monitoring vulnerable patients and residents closely, and recognising the early signs of heat-related illness.

As extreme weather events become more frequent, researchers say protecting vulnerable people from heat should remain an important public health priority alongside ongoing planning for winter pressures.

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