Maryland Department of Health issued the following announcement on July 2.
The National Weather Service has issued Heat Advisories for Dorchester, Inland Worcester, Somerset, Wicomico, Caroline, Cecil, Kent, Queen Anne's, Talbot, Anne Arundel, Calvert, Carroll, Howard (Central & SE), Montgomery (Central, SE & NW), Charles, Frederick, Baltimore (Northern & Southern), Harford (NW & SE), Howard (NW), Prince George's, St. Mary's, Allegany (Central & Eastern), and Washington Counties until 8 p.m. Stay cool, stay hydrated, and stay informed.
Original source can be found here.
Source: Maryland Department of Health