Heat Wave Strikes U.S.

From Northwest To The Northeast, Baking Heat And Stagnant Air Excessive heat -- with temperatures as much as 20 degrees or more above average -- continues to besiege much of the continental United States today. Cooling centers have been opened in major cities, including New York City, and the Pacific Northwest has is ground zero for an excessive heat warning. 90-degree heat is expected throughout the lower two thirds of the nation today, and many parts of the West and Southwest will top 100. According to Accuweather.com, the Northeast -- from New Hampshire and Vermont south into the Mid-Atlantic -- will feel, given high humidity, well above 90 degrees. A National Weather Service heat advisory is in effect as far south as South Carolina. Air quality is poor in many of these regions, due to ground level ozone -- also known as smog. Smog forms when emissions from vehicles and power plants and factories mingle in sunlight and intense heat. The resulting pollution can cause respiratory illness, circulatory problems and lasting lung damage. It also causes that hazy film in the air that obscures the view. Sensitive people are advised to stay indoors -- not only due to the heat, but to the increased risk of respiratory or heart failure. More on the Blazing Summer/Global Warming: Stories and Tips Cool Home Design (Passive Solar) Keeping Your Cool (Easy Home Tips) Heat Wave -- Global Warming Revealed? Global Warming Skeptic's Argument Debunked Climate Skeptic Changes Tune, and Makes Warming a Conservative Issue List of 10 Biggest Wildfires Now Burning Stay Cool Recipes Chilled Cucumber-Melon Soup with Radish Salsa Strawberry Granita Tomato, Fava Bean and Smoked Gouda Salad Your Photos Heat Wave Photos sent to Weird Weather Watch Heat Waves Heat Waves 2 That's Hot Fried Eggs and Shadows Porsche in the Heat Waves What does the heat wave look like to you? Send us your heat wave photos