As the United States heads into a milestone July 4 holiday this weekend, parts of the Northeast are preparing for hazardous levels of heat.

As millions plan to celebrate the Fourth of July outdoors, meteorologists warn temperatures could soar to record-breaking, life-threatening highs.

The nation is gripped in a dangerous heat dome. Threatening millions of people in the Midwest and Eastern United States.

High humidity is expected to make conditions feel even hotter