Residents visited Locust Lake State Park in effort to keep cool Monday as temperatures soared into the 90s. The park will likely be a popular spot as the heat sticks around for a few days. The National Weather Service has issued a heat advisory until 8 p.m. Wednesday. Heat index values could top 100. Heat related illnesses increase significantly during extreme heat and high humidity events. During extreme heat, it’s best to drink plenty of fluids, stay in air-conditioned rooms, stay out of the sun, reduce outdoor work and check up on relatives and neighbors.