India, May 29 -- The opening chapter of Kim Stanley Robinson's novel The Ministry for the Future (2020) is set in India, amid a heatwave.

In one small town, electricity has failed.

The wet-bulb temperature, a metric that combines air temperature and humidity to indicate whether humans can cool off via sweating, has crossed a dangerous threshold.

People wade into a lake to survive.

But the lake has heated up, and they perish there.

Of course, it's science-fiction. Or is it?

And for how long?

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When the first prime minister of Singapore, Lee Kuan Yew, was asked in 1999 what made his country's transformation possible, he listed air conditioning as a key factor.

He added that, as a technology, it had changed the nature of civilisat...