Growing up the main meal was lunch. The food was covered with a table cloth and left on the table until dinner time. Now we can use the microwave to reheat if wanted, back then you ate it at room temp. If you are healthy no problem with some bacteria. The very young or anyone unhealthy shouldn't be eating room temp food left on the counter for more then a couple of hours. I remember my grandmother making my great grandmother a hot meal for dinner as everyone knew leftover food was bad for the very old.