More than 2,700 people are estimated to have died in the UK from heat-related causes during the extreme heatwaves that swept across Western Europe in May and June, according to expert analysis reported by the BBC. The figure comes from a joint assessment by researchers at Imperial College London, the UK Met Office, and the London School of Hygiene & Tropical Medicine.
Record-Breaking Temperatures
Most of these deaths likely occurred during the June heatwave—the hottest June ever recorded in England—when temperatures soared to 37.7°C (99.9°F) in Lingwood, Norfolk. That broke the previous record of 35.6°C (96°F), set in 1957. At the time, the UK issued a rare red weather warning for extreme heat across parts of England and Wales—a level of alert that warned even healthy individuals of life-threatening risks.
May also saw unprecedented heat: on 26 May, temperatures hit 35.1°C at Kew Gardens in London—the highest May temperature ever recorded in the UK, surpassing the prior record of 32.8°C set in 1922 and matched in 1944.
A ‘Heat Dome’ Intensified by Climate Change
Both heatwaves were driven by a persistent ‘heat dome’—a stationary area of high atmospheric pressure that trapped hot air over the region. Experts say human-caused climate change intensified this event. Since pre-industrial times, global average temperatures have risen by approximately 1.4°C—and scientists estimate this warming added between 3°C and 4°C to the peak temperatures observed in May and June.
Hot, tropical nights worsened conditions, offering little relief. Many UK homes lack features like insulation or ventilation designed to cope with such extremes, leaving residents vulnerable to prolonged, dangerous heat exposure.
Health Risks and Vulnerable Groups
Extreme heat places enormous physical strain on the body—especially when combined with dehydration. The heart must work harder and faster to cool the body, increasing stress on the cardiovascular system. Infants, older adults, and people with pre-existing health conditions face the highest risk. This can trigger spikes in heart attacks, strokes, and other potentially fatal medical emergencies.
Heat affects everyone—even those in good health—and is often called a ‘silent killer’ because early symptoms—such as fatigue, dizziness, or confusion—are easily overlooked. When hot air is also humid, as it was in June, the body’s ability to cool itself through sweating is significantly impaired.
Future Outlook
The study draws on mortality data from previous years to model excess deaths linked to the heat. As global temperatures continue to rise, experts warn that such intense, frequent heatwaves are likely to become more common across the UK and beyond.