Heat index in northeastern US tops 100

Girl, 11, dies in hot car on Long Island

NEW YORK — Tens of millions of people in the northeastern United States sweated in dangerously high heat Wednesday, with temperatures that felt like more than 100 degrees and prompted emergency measures including school closures and extra breaks for star players wilting at the U.S. Open tennis tournament .

Authorities on Long Island say heat appeared to be a factor in Tuesday’s death of an 11-year-old girl found in a vehicle with the windows closed. The heat index was past 100.

In Massachusetts, nearly two dozen school districts canceled classes or sent children home early Wednesday in response to heat that reached 98 degrees, breaking the Aug. 29, 1953, record of 96. With the added high humidity, it felt like 107 degrees, according to the National Weather Service.

“Our schools were simply not designed for the sustained heat and humidity we are experiencing since many do not have air conditioning or sufficient cooling systems,” said Mike Morris, superintendent of the Amherst-Pelham Regional School District, in a message to parents.