Sara Berg said Tuesday that she replied "thank God for you," to Canadian motorist Victor Giesbrecht's remark on Saturday.
The 61-year-old Giesbrecht went into cardiac arrest shortly after he and his wife pulled back onto the highway near the town of Menomonie.
Berg and her cousin, Lisa Meier, saw Giesbrecht's wife waving for help and pulled over. They then performed CPR on the Winnipeg man until help arrived.
Giesbrecht remained hospitalized Tuesday in serious but stable condition. His wife issued a statement Monday crediting Berg with saving her husband's life.