A 32-year-old Stoughton man is being held in the Dane County Jail after he was found unconscious in a vehicle Saturday night. Sheriff’s deputies gave Joshua Gavney two shots of Narcan to help him with a possible opioid overdose. Gavney was arrested on tentative charges of heroin possession and operating while intoxicated, fifth offense. A 9-1-1 caller told authorities about a driver who had stopped his vehicle on County Highway B in the town of Christiana. Gavney was treated at a local hospital, then transported to the jail.