UPDATE: Avis Barbara Foster has been located and is safe, the Collier County Sheriff's Office reports.
Collier County deputies are asking for the public's help in locating a 80-year-old woman who has been missing since Monday morning.
Avis Barbara Foster was heard from by her son Monday morning in the North Naples area.
Deputies believe she may have a medical condition.
Deputies said Foster is described as white, 5 feet 1 inches tall and 90 pounds with silver hair and blue eyes. Her clothing description is unknown. She may be driving a red, four-door Toyota bearing FL license plate M55JR.
Anyone with information about Foster's whereabouts is asked to call the Sheriff's Office at 252-9300.