The problem is that you have to air the sealed container regularly(I find once a day airing to speed up the process). By airing, you dislodge some of the tiny eggs laid by flies around the lid, which then fall into the high-meat mess below, and you then get maggots crawling all over sooner or later. I've managed, by being ultra-careful, to avoid such a thing happening, over a 3-week period, but one always forgets sooner or later.
Ah, well I have it sitting in a closed drawer in my room (as good as a refrigerator, just without the cold, right?)
So flies probably aren't a problem. If I observe maggots, I guess I will have learned a lesson and put future jars in the fridge.
That being said, do you have any idea about time difference between cooled and uncooled?