Never reheat food in plastic
Even if your food containers are labeled as one of the safe plastics, always transfer food to a glass or china dish before reheating in the microwave. All plastics contain possible harmful chemicals, and when heated, those chemicals can leech onto the food that is next to them. Take-out containers are one of the worst culprits when it comes to plastics that contain toxic elements, so never reheat food in those containers.
Clever, practical, interesting, odd...you be the judge.