(Washington, DC) — A heat wave is rolling through the District of Columbia. Highs are in the 90s today and a Code Orange Air Quality alert is in effect. Code Orange means air-pollution concentrations in the region may become unhealthy for young children, the elderly, people with asthma and those with a heart or lung condition. People in those sensitive groups should limit outdoor activities. Ninety-degree weather will continue through Friday and Saturday with higher humidity.