Searing heat returns to Nashville

After a brief break from extreme heat , scorching conditions are returning to Nashville.

State of play: A heat advisory is in effect for Middle Tennessee from 12-7pm Tuesday. Heat index values up to 109 are expected, according to the National Weather Service.

• The forecast is unrelenting, with highs expected to remain in the high 90s through Friday.

Threat level: Those conditions could cause life-threatening heat illness. Experts advise residents to drink plenty of water and stay out of the sun.

What we're watching: The next big heat wave is expected to send temperatures soaring well above normal in much of the country into next week, NOAA predicts .