A woman uses an umbrella to shelter herself from the sun and heat on the National Mall near Capitol Hill in Washington June 9, 2011. Temperatures in the area are expected to exceed 100 degrees Fahrenheit (38 degrees Celsius). [Photo/Agencies]

A woman is silhouetted against a water fountain as she takes a drink at the Hirshhorn Museum and Sculpture Garden in Washington June 9, 2011. Temperatures in the area are expected to exceed 100 degrees Fahrenheit (38 degrees Celsius). [Photo/Agencies]