COLUMBIA (AP) ó The National Weather Service has issued a heat advisory for much of eastern South Carolina.

The weather service said the warning about excessive heat was in effect Monday from midday until early evening.

Forecasters said heat index values as high as 110 degrees were possible because of temperatures in the mid- to upper-90s and high humidity.

The advisory was in effect in Allendale, Berkeley, Colleton, Charleston, Dorchester, Florence, Georgetown, Hampton, Horry, Jasper, Marion and Williamsburg counties.

Forecasters warn the combination of heat and humidity could lead to heat illnesses unless proper precautions are taken. People who must be outside should drink plenty of fluids, wear light-weight clothes and stay out of direct sunlight if possible.

Itís best to do strenuous outdoor activities in the early morning or evening.

Heat advisory posted for parts of state