Life-threatening heat remains one of our biggest headlines as temperatures hit the 90s and even the 100-degree mark across the Great Lakes, Ohio Valley, and Northeast.

Dangerous heat continues to build across the Midwest and Northeast, and more records will likely be smashed in the coming days. A record high of 97 degrees was set at Chicago O'Hare airport on Monday, beating the previous record of 96 degrees set in 1887 and tied in 1957. More than 80 million are under heat alerts today and this heat wave is expected to persist for days.

In addition to hot afternoons, warm nights bring their own issues. With lows in the mid-70s, it will be difficult for folks to cool down. You will want to keep an eye on the TemperatureRadar today to determine when the hottest weather will move into your region.

Today's highs reach the low and mid-90s in cities like Chicago, Pittsburgh, Louisville, Ky., Washington D.C., Boston, and Burlington, Vt. You will also want to keep an eye on the "feels like" temperatures, which will soar into the low triple-digits with the above-average humidity.

The Ohio Valley and Northeast will continue to have daytime highs 15 to 20 degrees above average through at least Thursday. This persistent heat is dangerous to your health. Stay hydrated, wear light clothing, and take breaks in the shade or indoors as often as possible if you work out in the heat.