A dangerous set-up of hot temperatures and high dewpoints will mean millions of Americans from the Ohio Valley to the Gulf Coast will be in store for an unbearable heatwave during the upcoming week.

Meteorologists say a strong upper-level ridge of high pressure, which will park itself over the Southeast, will help send temperatures soaring into record territory.

As a result, more than 70 million Americans from coast to coast are under some type of heat alert as temperatures creep higher and higher over the next several days.

Forecast models indicate parts of the Ohio Valley and mid-South could see temperatures 20 to 30 degrees above average as that ridge of high pressure expands across the region.

And those temperatures don’t take into account the humidity, which will cause the heat index to easily rise above 100 degrees in many areas.

Every day of the heatwave could challenge dozens of record high temperatures.

Here’s what you can expect over the next several days.

Monday forecast

Triple-digit heat will be possible as far north as Nebraska on Monday as an area of high pressure slides eastward.

The warm temperatures mean dozens of daily record highs are in jeopardy from the Rockies and Southwest to the East Coast.

When the actual heat is combined with the humidity, it could feel like temperatures are between 100 and 110 degrees across large parts of the South.

The record heat will only slowly progress eastward for Tuesday.

Here’s a look at some of the high temperatures on Monday.

Alexandria, Louisiana, Little Rock, Arkansas and Tuscaloosa, Alabama, are expected to be about 95 degrees, but to the north in Nashville, the temperatures are expected to reach about 100 degrees.

Atlanta will also be very hot, with a high temperature of about 96 degrees.

Tuesday forecast

Tuesday will feature record highs from the Great Lakes to the Southeast.

Cities as far north as the southern suburbs of Chicago could see the mercury reach 100 degrees.

Typically, the Windy City only reaches a high of around 80 degrees during this time of year.

Dozens of other cities will either approach or break records on Tuesday afternoon as millions of Americans see temperatures reach the 90s and even 100s.

The dangerous heat will continue to expand east on Tuesday, with areas of the Carolinas getting above 100 degrees during the day.

But those triple-digit temperatures won’t be felt in that area alone.

St. Louis, Nashville and Knoxville, Tennessee, and Louisville, Kentucky, will all get close to the century mark.

Heat precautions

When this dangerous heat arrives, it’ll be imperative to take the proper precautions to stay cool and stay safe.

First off, try to limit the time spent outdoors during excessive heat. The best time to be outdoors would be early in the morning or later in the evening.

If you need to go outdoors during the day, wear loose, lightweight and light-colored clothing and drink plenty of fluids.

Always “look before you lock” to ensure you have not left any children or pets inside a car. Temperatures inside a locked vehicle with the windows rolled up can be deadly.