Pop-Tarts heated on the dashboard are quite acceptable and never over-heat to tongue-burning temperatures.
More advanced survival cooking:
During college, my brother used to set a can of Chef-Boy-R-Dee on the radiator in the morning before he went to class. He swore that it was the ideal mid-afternoon snack on a cold winter’s day.
My sister perfected the dorm room grilling of a grilled cheese sandwich.
Cover the bottom of an iron with aluminum paper. Butter bread on both sides. Set on a plate. Remove plastic wrap from American cheese-food product. Take one slice of buttered bread and lightly press on warmed aluminum-foiled iron. Once it starts to steam a little, flip bread. Do the same thing to the other slice of bread.
Now, add the slice of cheese product to bread and press the top slice of bread over the cheese.
Be patient! Cold cheese sandwiches are nasty.
Finally, there is super-advanced survival cooking:
When I was in college, we discovered that the Foreign Language building had a mini-kitchen. We trekked to the hardware store in the village and bought a pan. When the mood struck us, and when the language lab was open at night, we would sneak our pan in and make pasta. A strand of pasta would be tossed at the ceiling with a vindictive, “The best tense in Italian? The pasta perfect!”