 WFMD News. The National Weather Service says a heat advisory remains in effect from now until 8 p.m. Heat index values could reach up to 109 degrees. Hot temperatures and high humidity can cause illnesses to occur. And the Weather Service advises you to drink plenty of fluids, stay in air-conditioned rooms, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances.