 There's a heat advisory from 11 a.m. to 8 p.m. for Dorchester, Wicomico, Somerset, Inland Worcester, Acomac, Northampton, Cape May, Atlantic, and Cumberland counties. Now, the what exactly is as follows. Heat index values up to 110. Dangerously hot conditions and, of course, heat-related illnesses can increase significantly during extreme heat and high humidity events. Please take the necessary precautions.