A heat advisory for Columbia County will remain in effect from 11 a.m. to 7 p.m. Thursday.
An advisory for Wednesday pegged a heat index value up to 107 degrees. The National Weather Service in Shreveport said the Thursday advisory is for heat index values up to 109.
Portions of north central and northwest Louisiana, south central and southwest Arkansas and east and northeast Texas are included in the advisory.
Hot temperatures and high humidity may cause heat illnesses to occur.