How Harmful Is Accidental Intake Of Molten Plastic In Food?

I accidentally ate some food which may have had melted plastic on it, I heated it up in the oven. I know that it wasn't smart. Do i need to go to the ER. When i took the meal out of the oven the cover had shrunk to half its size. I threw what was left of the cover out. How worried should I be? Do i need to go to the hospital. I ate about a quarter of the food.