Do cats like their food heated?

No, cats do not like their food heated. They like their food at room temperature.

This is one of the biggest problems with wet food: what to do with the leftovers. You can't leave the food out, because it will spoil. But you can't put it in the fridge, because they won't eat it cold. But they also won't eat it if you warm it up in the microwave. So you have to make sure they eat all of it in a matter of hours.