99.5 Jetta overheating after oil change

I took my late model 99 Jetta in to check the brakes and to get the oil changed from an independent garage that I trust very much. When I picked up the car, I got 5 miles before the engine began to overheat and I had to pull over. I couldn't drive it back to the garage. The coolant level was fine, and I never have issues with this car. What could have happened? I know its possible that this is a coincidence, as it has 134K on it, but that doesn't sit right with me. Any thoughts?

maybe they unpluged the electric fan when they where changing the oil,may have bin a accedent