The Upper Darby Fire Department was dispatched Saturday night about 8:20 to the 200 block of Kingston Road for sick individuals, and personnel learned of high carbon monoxide readings.
According to Delaware County fire radio traffic:
At least three individuals were treated by medics.
One reading was as high as 400 parts per million.
Crews began ventilating the residence and other houses nearby and the incident was placed under control in a half-hour.
Official details were not yet available.