It said that, based on CDC guidance, no special action was indicated for the passenger or for anyone else on the flight.
The incident appeared to demonstrate increased attention to the possible hazards posed in the United States by the viral outbreak in China.
The passenger, who had been in Beijing, arrived at BWI on a flight from Las Vegas, the health department said.
Southwest Airlines said its crew on Flight 2889, in following CDC recommendations, acted out of “an abundance of caution” in light of recent coronavirus concerns.
The recommendations are to ensure that passengers and others flying with them get the aid or support they might need, the airline said.
After being evaluated by medical personnel, the health department said, the passenger was released.