A new forecast from climate researchers raises the alarm over the human cost of extreme temperatures: up to 451,000 additional heat deaths over the next six months. The estimate is not presented as a certain figure, but as a projection based on the historical link between intense heat and mortality, at a time when El Niño is developing on top of an already hotter climate.
Projection for the September 2026-February 2027 period
According to the researchers, the period from September 2026 to February 2027 could be accompanied by a significant rise in heat-related deaths. The figure of 451,000 additional cases comes from comparing high temperatures with the effects they have historically had on mortality.
The analysis was built on data from 24,378 regions worldwide. The researchers compared month by month temperatures and additional heat deaths for the 1996-2025 period, then combined those data with temperature forecasts linked to El Niño.
Which countries are seen as most exposed
According to the assessment, tropical countries are expected to bear the heaviest burden. Nigeria, Indonesia, Sudan, India and Brazil are ranked among the areas where the highest loss of life linked to extreme heat is projected.
The United States is also included in the projection, with about 3,500 additional heat deaths expected during the same period. This shows that the impact is not limited only to poorer countries, even though exposure and coping capacity remain deeply unequal.
The risk does not stop at temperatures
The researchers warn that the consequences of a powerful El Niño are not measured only by the thermometer. The phenomenon could simultaneously bring droughts, fires and floods, adding pressure on health systems, agriculture and water supplies.
If agricultural production and supply chains are hit, immediate consequences could be felt in food security and prices. The World Food Programme has warned that a strong El Niño could push about 50 million people toward acute hunger.
What researchers are asking of authorities
According to reporting by The Guardian, the researchers argue that such projections could give authorities a window for earlier response. Measures mentioned include better heatwave warnings, opening cooling centers and increasing health staff during the most critical hours.
The need for stronger protection for workers exposed outdoors to high temperatures is also mentioned. The experts’ warning is that events considered extreme today could become more frequent, while El Niño acts on top of the accumulated effect of global warming from greenhouse gases.
At its core, the alarm is not only about a cyclical natural phenomenon, but about the fact that it is striking a climate that has become hotter and more unstable.
This makes every projection for loss of life, food and water not simply a matter of weather, but a serious test of the readiness of public institutions.