More people died from the heat last year, than from earthquakes, hurricanes and floods combined, reveals a newly released Swiss Re report, making extreme high temperatures one of the world’s most important emerging risks.

According to the firm’s latest Sonar report, up to half a million people globally succumb to the effects of extreme heat each year.

On May 14, San Antonio, Texas, saw temperatures hit record highs, topping 100F almost a month earlier than usual, going as high as 103F.

Temperatures also broke records in southern and central England this year, when the thermometer hit 80F in April.

The Swiss Re study highlights how this peril reaches beyond the human toll, mapping its effects across industries such as the energy and telecommunications sectors.

“Extreme heat used to be considered the invisible peril because the impacts are not as obvious as of other natural perils,” said Jérôme Haegeli, Swiss Re’s group chief economist.

Mr Haegeli said, with a clear trend to longer, hotter heatwaves, it is important to shine a light on the true cost to human life, the economy, infrastructure, agriculture and healthcare systems.

Swiss Re said there is clear evidence that extreme heat events are happening with greater severity, frequency and duration.

Last July brought the three hottest days recorded on Earth. “Data is also emerging to show that, since the 1960s, heatwaves in the United States are now three times more prevalent, are almost a full degree hotter, and last a full day longer,” the report stated.

Recent data shows that about 480,000 deaths per year can be attributed to extreme heat events.

Heat stress can lead to exhaustion, heatstroke and organ failure, while exacerbating cardiovascular and respiratory diseases.

People at an advanced age and pregnant women are especially vulnerable.

Heatwaves that coincide with strong winds can also increase the likelihood of wildfires.

According to Swiss Re Institute, global insured losses owing to wildfires reached $78.5 billion between 2015 and 2024.

The Sonar report reveals that a range of industries are vulnerable to extreme heat events. For example, the telecommunications industry faces significant risks from failing cooling systems in data centres or damage to terrestrial cables.

Liability risks have already started to emerge, with corporates and institutions facing legal action for failing to mitigate heat-related harms.

A 2021 lawsuit saw a US plaintiff seeking $52 billion from fossil fuel companies for losses caused by climate change-induced extreme weather events.

Extreme heat is therefore set to intensify litigation which, in turn, drives up liability claims for insurers.

Patrick Raaflaub, Swiss Re’s group chief risk officer, said amid an increasingly interconnected risk environment, insurers are having to continuously adjust the scope of their risk horizon.

He said the conversation must evolve beyond individual topics to examine how large macro trends are now reshaping today’s risk landscape.