Chestertown, MD – Emergency services officials in Kent County said 36 people had to be assessed after a carbon monoxide leak Monday morning.

The incident happened at the Department of Social Services building in the 300 block of High Street in Chestertown around 10 a.m., officials said.

Officials said three dozen people received treatment at the scene, but no one went to the hospital. They said the source of the leak came from a mechanical malfunction in the heating system.

The building has since been reopened.