Extreme heat summit to urge leaders to act on threat from rising temperatures

People are seen at the dried-up riverbed of the Jialing river, a tributary of the Yangtze River in China's southwestern city of Chongqing. One study says China is on track for between 20,000 and 80,000 heatwave deaths a year.

Two of the world’s biggest aid agencies will host an inaugural global summit on extreme heat on Thursday as directors warn that the climate crisis is dramatically increasing the probability of a mass-fatality heat disaster.

After last year’s record-shattering temperatures, when 3.8 billion people — half the world’s population — sweltered in extreme heat for at least one day, the organisers hope the event will prompt governments to prepare for a “silent killer” that rarely gets the attention it deserves when compared with hurricanes, tsunamis and earthquakes.