It is generally recommended to poke holes or create vents in the plastic film covering a TV dinner before microwaving it. Failing to do so can have several potential consequences:
Steam buildup: When food is heated in the microwave, steam is released. If the plastic film is not pierced or vented, the steam can build up inside the package, creating pressure. This pressure can cause the plastic film to expand or even burst, potentially resulting in a mess and potential burns from the hot steam.
Uneven heating: The purpose of venting the plastic film is to allow steam to escape during the heating process. Without vents, the steam is trapped inside, and the pressure can create an uneven cooking environment. This may result in some parts of the meal being overcooked while others remain undercooked.
Condensation and sogginess: Without vents, the trapped steam can condense on the plastic film and drip back onto the food. This can lead to sogginess and affect the texture and taste of the meal.
Potential hazards: In rare cases, if the pressure inside the package becomes too great, the plastic film can burst or rupture, causing hot contents to spill out. This can lead to burns or other injuries.
To avoid these issues, it's generally recommended to follow the instructions provided on the packaging of the TV dinner. Most TV dinners will have instructions to poke holes or create vents in the plastic film before microwaving. These vents allow steam to escape, promoting even heating and preventing pressure buildup.