New York and Washington, D.C., could see temperatures surpass 90 degrees for up to a week. For people with air-conditioning, window units and central air will be humming for days on end. While staying safe and staying cool is paramount,

An extremely dangerous heat wave is predicted to hit the Midwest and the East Coast on Monday and Tuesday, with the National Weather Service warning that triple-digit heat is expected.

More than 150 million Americans are under the highest-level extreme heat alerts during a wave of above-average temperatures.