Chicago Police Superintendent Eddie Johnson became ill and wavered on his feet during a news conference Friday morning.
Chicago Mayor Rahm Emanuel was speaking at a podium with Johnson standing beside him when the mayor stopped suddenly and turned to the police superintendent saying, "Are you OK?" People then surrounded Johnson, who appeared dazed as he walked toward a chair.
Several people shouted: "Call 911."
Chicago Police Department spokesman Anthony Guglielmi said on Twitter that Johnson "felt light-headed" and didn't lose consciousness. Guglielmi says Johnson was coherent and will go to a hospital to be examined.
Johnson and the mayor were announcing technological advances for police as the city deals with increases in homicides and shootings in recent years.
A spokesman says Chicago Police Superintendent Eddie Johnson's bout of dizziness is unrelated to a "longstanding kidney issue."