Fumigating Soon. Do the plastic bags work?

I am fumigating my house soon because of a termite infestation and they said I have to bag up all opened food but that it can stay in the house. Are the bags enough? Should I be concerned if I keep food in my house even though it's bagged? Also what should I do about my mattress and sheets? If you have any advice or experience with fumigating your whole house that would be helpful!