The National Weather Service is warning South Carolina residents to stay cool following a predicted heat index of 109 °F on Saturday, with hot temperatures continuing into next week.

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.

A heat advisory will be in effect Friday. While thunderstorms will cool things down for the weekend, the extreme heat will return early 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.

Meteorologists warned that the oppressive heat wave is part of a larger system impacting much of the Southeast and Midwest.

The National Weather Service has issued a severe thunderstorm watch for Connecticut. The entire state is under the severe thunderstorm watch, according to the National Weather Service. The watch is in effect until 9 p.m., according to the National Weather Service.

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

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.