From Texas to New England, millions of Americans are facing dangerously hot temperatures that have led the National Weather Service to issue heat advisories and extreme heat warnings this week.

The National Weather Service issued a heat advisory for Friday, predicting the heat index will hover around 100 degrees for the next week.

The National Weather Service’s Fort Worth office extended the heat advisory for the Metroplex through 9 p.m. Saturday. Rising humidity is expected to push the heat index, or “feels like” temperature, into extremely unpleasant territory, with some parts of the region possibly reaching 108.

Much of the U.S. is under extreme heat warnings or advisories while New York, Philadelphia and Washington could feel like 100 degrees or more.

EDT the National Weather Service released a heat advisory valid for Wednesday between 2 p.m. EDT and 8 p.m. EDT for Cass and Berrien counties.

A heat advisory was released by the National Weather Service on Monday at 12:23 a.m. valid between 10 a.m. and 6 p.m. for Geneva and Houston counties.

The National Weather Service already has issued extreme heat warnings, watches and advisories across a swath of the Midwest and South.

Here we go again! We’re tracking more dangerous heat in Greater Boston today and tomorrow. And on top of that, a few storms could be strong to severe tomorrow afternoon. A Heat Advisory is in effect for much of our area until 8 p.