oston broke a daily record high temperature Sunday and New York City and Philadelphia may follow suit as an "extremely oppressive" heat wave intensified in the Northeast, leading to at least two heat-related deaths over the weekend.

More than 85 million Americans faced excessive heat warnings and advisories Sunday from the Southern Plains to the Northeast, according to a National Weather Service statement.

In New York City, the city's medical examiner's office confirmed one person died as a result of heat exposure Saturday. The person had heart disease and emphysema, which contributed to the death, the medical examiner’s office said.

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In Pennsylvania, a 73-year-old man died from heat-related complications Thursday, NBC Philadelphia reported, amid a stretch of 90-plus degree days for the state. Philadelphia could approach 100 degrees Sunday, a forecasted temperature that would break the three-digit mark for the first time in a decade.

Is there relief in sight? A cold front approaching the Northeast on Monday and Tuesday should bring some less oppressive temperatures, according to the National Weather Service, but there is also the possibility of severe weather in the form of thunderstorms and high winds.