The Pennsylvania Department of Environmental Protection is predicting potentially unsafe ozone pollution in Philadelphia.
The Code Orange air quality action day means people with breathing problems should limit outdoor activities. People are also urged to limit pollution-producing activities like fueling cars after dusk, and are urged to carpool or reduce the number of vehicle trips they take.
Code Orange is the second highest pollution warning, and means the air is unhealthy for those sensitive to pollution. A Code Red alert means the air is unsafe for everyone.
The pollution forecast was driven by a weather forecast calling for sunny and hot conditions and temperatures of about 90 degrees.