 Now to the top stories we're working on at WTOP. There's an excessive heat warning in effect today for many of us starting at noon, and we won't get even a brief break from this heat wave until Friday. What's happening behind the scenes at the NATO summit in D.C.? And there's encouraging news about the health of the Chesapeake Bay. Keep it here. We will bring you full details on these stories and more in the minutes ahead. 948.