Heat Advisory In Effect Until 8 PM Thursday

...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...* WHAT...Heat index values around 105 expected.* WHERE...Portions of central, north central, and northern Maryland  and northern Virginia.* WHEN...Until 8 PM EDT this evening.* IMPACTS...Hot temperatures and high humidity may cause heat  illnesses.PRECAUTIONARY/PREPAREDNESS ACTIONS...Drink plenty of fluids, stay in an air-conditioned room, stay out ofthe sun, and check up on relatives and neighbors.By THe National Weather Service, Sterling, Va.