Severe heat waves across Europe this summer resulted in an estimated 50,391 deaths in cities and towns, according to peer-reviewed studies released by scientists at Imperial College London and collaborators.

The findings, published in the journal Nature Health, mark this summer as the deadliest for heat-related mortality on the continent this century. The total far exceeds previous peaks of roughly 29,000 deaths in 2022 and 28,000 in 2003. Researchers modeled excess deaths linked to high temperatures in 854 urban areas across 30 countries, covering about 40 percent of the population in those nations.

About two-thirds of the deaths, or roughly 32,600, were attributed to additional warming from human activities. Southern and western Europe suffered the worst impacts, with Italy recording an estimated 13,303 deaths, followed by France with 7,268, Spain with 6,824, and Germany with 6,340. The United Kingdom saw about 4,354.

A particularly intense period from June 17 to July 1 accounted for nearly a third of the toll, when temperatures averaged more than 5 degrees Celsius above normal. The studies relied on statistical models incorporating demographics, health services, and historical temperature-mortality relationships rather than official death certificates, which often undercount indirect heat effects on cardiovascular and respiratory conditions.

The analysis underscores vulnerabilities in infrastructure not built for such extremes, especially in northern regions unaccustomed to prolonged high temperatures. Governments issued heat warnings during the waves, but the scale of the estimated fatalities highlights ongoing challenges in protecting vulnerable populations, including the elderly who comprised the majority of cases.