Fireworks, beach trips, and backyard gatherings are staples of the Fourth of July holiday. This year, however, many Americans may need to add heat safety to their plans. Forecasters say a prolonged stretch of extreme temperatures and high humidity could affect much of the country heading into the holiday weekend.

Which areas could see the most extreme heat?

Leading up to and through the July 4 holiday weekend, much of the eastern half of the United States could face dangerous heat and humidity, according to a new outlook from the National Weather Service (NWS), part of the National Oceanic and Atmospheric Administration (NOAA). The high temperatures are expected to last from July 2 through at least July 5.

"Significant, dangerous heat wave expected next week for the

Central to Eastern U.S., the agency stated.

A high risk of extreme heat is in place for parts of the Mid-Atlantic and Southeast from July 2 to July 4, as well as portions of the Ohio Valley, Tennessee Valley, Great Lakes region, and Middle Mississippi Valley from July 2 to July 3. A broader moderate risk extends across much of the central and eastern U.S.