The National Weather Service of Shreveport, La., issued a heat advisory from 3:09 p.m. Thursday until 7 p.m. Friday.
The heat advisory affects Bowie and Cass counties in Texas; Miller, Little River, Hempstead and Sevier in Arkansas; and Caddo Parish in Louisiana, among other areas.
The NWS explained that a heat advisory is issued when hot temperatures and high humidity combine to cause a "situation in which heat-related illnesses are possible."
"A heat advisory means that a period of hot temperatures is expected," the NWS advisory states, recommending that residents in affected areas drink plenty of fluids, stay out of the sun and in air-conditioned areas and check on relatives and neighbors.
The Occupational Safety and Health Administration is cited in the advisory as recommending outdoor employers and employees to schedule frequent rest breaks in shaded or air-conditioned environments.
"Anyone overcome by heat should be moved to a cool and shaded location," according to the advisory.
"Heatstroke is an emergency. Call 911," it states.