That's basically what I do, but my reptile room has a small fridge and freezer which holds food for the snakes, iguana, cat and ferret. I take out the rats the night before and stick in the fridge, then I take them out and set on the fridge to hit room temp while we go have breakfast, come back and feed snakes. I warm them up with a hair dryer for the ones who like that. Like bcr229 said, it depends on the size of the feeder too, on the weeks only a couple smaller snakes get fed I'll often take out their feeders and leave out on the fridge for a couple hours and they are good to go. Bigger ones you have to plan ahead better for.