Scientists from the World Weather Attribution (WWA) group said the heatwave in the Indian Ocean island, which affected millions of people, "would have been virtually impossible without human-caused climate change".

The study by 13 researchers looked at three variables to investigate the heatwave: the island's average temperatures over October and the seven-day minimum and maximum temperatures in the country's capital Antananarivo.

"The analysis found that human-caused climate change made the month-long heat, seven-day maximum temperatures and seven-day minimum temperatures about 1-2°C hotter," the WWA report said.

While the temperature increase might not seem like much, Sayanti Sengupta, technical advisor at Red Cross Red Crescent Climate Centre, said "an increase of even half a degree can push thousands more people to their physiological limit".

Sengupta added that it could also cause "heat stress" and loss of life.

Over 13,000 people in Africa have died in extreme weather events in 2023, more than any other continent this year, according to the EM-DAT international disaster database.

Yet extreme heat is severely underreported and understudied in Africa, the WWA said, which made it difficult to identify reported impacts of the dangerous temperatures in Madagascar and also impacts climate financing.

Around 91 percent of Malagasy people live in poverty, with many lacking access to clean water and electricity, which makes them "highly vulnerable to extreme heat".

And many live in informal housing which makes it more difficult to access coping strategies for heat.

Although October is the start of the hot and wet season, the temperatures were as high as the December and January period which is the height of the country's warm season.

"With heatwaves set to intensify in Madagascar, it is critical communities and governments take steps to become more resilient," said Rondrotiana Barimalala, senior researcher at the Norwegian Research Centre and the Bjerknes Centre for Climate Research.

Investments in early warning systems and extreme heat forecasting are of great urgency, the WWA said.