NEW YORK — Extensive triple digit heat, broken temperature records and oppressive humidity piled up into a steaming mess as the heat dome crushing the Eastern half of the nation sizzled to what should be its worst Tuesday.

New York City’s John F. Kennedy Airport hit 100 degrees Fahrenheit (38 Celsius) a little after noon, the first time since 2013.

Then Baltimore, Philadelphia and Boston joined the 100 club. More than 150 million people woke up to heat warnings and forecasters at the National Weather Service expected dozens of places to tie or set new daily high temperature records Tuesday. The dangerous heat sent people to the hospital, delayed Amtrak trains and caused utilities to urge customers to conserve power.

“Every East Coast state today from Maine to Florida has a chance of 100 degree actual temperature,” said private meteorologist Ryan Maue, a former National Oceanic and Atmospheric Administration chief scientist.

Fryeburg, Maine, also hit 100, for the first time since 2011.

— The Associated Press