Heat index values could reach 110 degrees in south Louisiana Friday afternoon _lowres

Advocate staff photo by LESLIE WESTBROOK -- Keymonte Prejean, 12, reacts to a jet of water as he plays in the fountain at Parc Sans Souci Monday, June 6, 2016, in Lafayette, La. He and other kids beat the heat in the splash pad Monday as the temperature approached 90 degrees.

Much of south Louisiana is under a heat advisory through Friday night, according to the National Weather Service.

The advisory, which includes the Baton Rouge and New Orleans areas, remains in effect until 7 p.m. Friday. Temperatures will reach low to mid 90s, and heat index values will climb between 105 and 110 degrees in the afternoons, the Weather Service said.

At that heat index level, people need to take precautions during outdoor activities against sunstroke, muscle cramps or heat exhaustion. People should drink more nonalcoholic fluids, take frequent breaks in activities and rest in shady areas when possible, according to the Centers for Disease Control and Prevention.

Heat index is how hot it feels outside when temperature and humidity are combined.