Tens of millions of Americans sweltered outside or sought air-conditioned refuge as an “extremely dangerous” heat wave blanketed the eastern United States on Tuesday with record high temperatures.

As a fierce sun reflected off the skyscrapers of New York, the normally frenetic Times Square was virtually deserted by mid-day as the mercury reached 99 degrees Fahrenheit (37 Celsius), the hottest since 2012 in the Big Apple.

By mid-afternoon Newark, New Jersey hit 103F (39.4C), according to the National Weather Service, and Philadelphia also reached 100F (38C).

New Yorkers walked under umbrellas as they navigated the streets of Manhattan, while others sunbathed in swimsuits in parks.

“It’s been kind of a cold spring. Then all of a sudden, boom, here it is,” Eleanor Burke, 82, told AFP of the heat, recalling how she took a dog for a walk the night before and “he almost looked like he was dead.”

Soaring temperatures are straining the city’s power grid as people crank up their air conditioning. In the Bronx, a New York borough, a blackout left more than 34,000 homes without power, prompting energy supplier Con Edison to urge residents to moderate their electricity consumption.

The NWS warned of East Coast temperatures of 97F-103F (36C-39.4C) on Tuesday, and a heat index — what the temperature feels like with humidity factored in -— spiking as high as 110F (43.3C) for the New York metropolitan area. AFP