India, June 23 -- On a scorching day in late May 2024, Delhi's fire service took 220 emergency calls, its busiest that year. Officials had said at the time that around 70% of the incidents they responded to were fires triggered by electrical short circuits. Across that summer, emergency response calls for fires more than doubled from a year earlier to cross 9,000, and deaths more than tripled compared to the 10 recorded during the same months the previous year.

Parts of Delhi that summer saw temperatures close in on 50degC, and scientists later confirmed 2024 to be the warmest year on record in global history.

That was a brutal year, but heatwaves have become increasingly common for much of north India. Every summer, the region sees the...