Paramedics responded to a family complaining they felt ill and discovered an increased level of carbon monoxide late Saturday at a home in west suburban Naperville.
About 9 p.m., a person called 911 to report multiple family members feeling sick at the home in the 1000 block of Bradford Drive, according to a statement from the Naperville Fire Department. They were advised to wait outside the building as firefighters and paramedics were dispatched.
Six minutes later, firefighters detected an increase in carbon monoxide levels, authorities said. The incident was elevated to an ambulance box alarm, bringing four additional ambulances and two commanders to the home.