The modelling puts Malta’s rate at 745 deaths per million people. Only Italy was higher, at 776 per million, with an estimated 13,303 deaths.

Researchers attribute 45 of Malta’s estimated deaths to human-caused climate change.

A new investigation by the Urban Journalism Network and with support of the Journalismfund Europe uncovered how heatwaves are estimated to have killed more than 50,000 people in cities across Europe, the largest this century. Nearly two-thirds of those deaths can be attributed to the effects of human-caused global heating.

The findings are based on research papers published in the journal Nature Health by scientists from Imperial College London and the London School of Hygiene & Tropical Medicine (LSHTM).

The new studies depend on epidemiological modelling by Masselot and his colleagues for 854 cities across the European Union, the UK, Norway and Switzerland. The analysis covers only urban areas and accounts for about 40 per cent of the population of the 30 countries included.

The team behind the new papers also used climate models to simulate the temperatures cities would have experienced in a world not gripped by the climate crisis. This “counterfactual” temperature record let them estimate the proportion of deaths attributable to human-made climate change, which has grown as the climate crisis has intensified.

Estimating the numbers killed by excessive heat is necessary because death certificates rarely record heat as a contributing cause.

Many people who die in heatwaves are discovered hours later. By then, their body temperature will have already dropped, making it impossible to know whether heat was the main factor, especially if they had underlying health problems.

In fact, a recent parliamentary question revealed that according to the National Mortality Registry, 20 people died “as a direct consequence of the heat in Malta and Gozo” in July this year.

This year was Europe’s deadliest summer, surpassing previous highs set in 2003 and 2022. Temperature records were set across Europe, and several cities experienced repeated heatwaves.

Older adults, people aged 85 and older, accounted for almost half of the estimated deaths.

Heat typically kills by straining the cardiovascular system and kidneys, as people sweat and pump blood to the skin to lose heat. The elderly and those with preexisting cardiovascular or kidney disease adapt less well as temperatures rise.

Younger people can also be impacted. Researchers estimate more than 830 heat deaths across 854 cities among people aged 20 to 44.

The highest proportion of deaths attributable to human-made climate change occurred in Estonia, Bulgaria and Finland.

How estimates are calculated:

The new studies used complex statistical models that linked daily temperature records with patterns of recorded deaths from January 2000 to December 2019 in more than 230 European cities with detailed daily death records, as described in an earlier study published in The Lancet Planetary Health.

Because vulnerability to heat varies with age, the researchers trained these models on death records for five age groups, from 20 to 44 years to 85 and older. They then built models that accounted for geographic location and a range of characteristics, including population density and socioeconomic factors, to extend the findings to a wider group of 854 cities.

The statistical modelling produced a series of “exposure response functions,” one for each city. These allow researchers to estimate the number of daily deaths likely to occur at any given temperature. Using daily historical temperature records, the researchers estimated the total number of heat-related deaths in each city for every summer, from June to August, since the turn of the century.

The same methods can also estimate deaths in a hypothetical climate without global heating. To do this, the researchers applied climate models to simulate daily temperature records for what they call a “counterfactual“ climate with no human-caused warming.

While the estimates come from statistical modelling based on recorded temperatures, they align well with estimates released by national health authorities, modelled from death records. For example, using similar methods, Imperial and LSHTM researchers earlier estimated that 2,700 people died across the UK during heatwaves that hit the nation in May and June 2026. Shortly afterwards, the UK Health Security Agency released its own estimate of 2,877, based on an analysis of death records.

However, because they depend on statistical modelling from historical death records, the new estimates cannot account for any measures taken in recent years to mitigate the death toll from heatwaves. So, in countries and cities that have aggressively implemented heat action plans, they may overestimate the heat-related death count.