Deadly ‘wet-bulb temperatures’ will be hotter due to climate change and heat waves

Some regions in India and Pakistan have been sweltering for weeks under a record-breaking heat wave. A billion of people exposed to dangerously hot conditions with little relief in sight.

While temperatures in the region cooled slightly this week, blistering heat is expected to return in the coming days and spread east, where rising "wet-bulb temperatures" — an esoteric measurement that was little known outside meteorology circles until now — could threaten the ability for humans to survive, according to experts.

As the intensity of heat waves increases as a result of global warming, it raises the risk that what's known as wet-bulb temperatures will also go up, pushing some heat events into "unsurvivable" territory, experts tell NBC.

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