In Chicago, where the weather is either hot, or brutally cold, the malls are not enclosed. At the Oakbrook Mall, which has lots of high-end shops, they disdain to even have the double-door "airlocks" that New Jersey stores have to keep the cold air out and the hot air in. I feel for the clerks at L'Occitane, for example, because the store is small and the doors are large, and when it is 5 degrees F below zero I can imagine them having pans of charcoal and flaming trashcans behind the counter to keep warm. Perhaps the mall brings in some extra plastic vestibule/porch affairs and places them over each door. I know the flowers are all brought in a truck and plugged in like little lightbulbs, and removed at the first sign of spoilage, and the fountains are drained and the pumps removed at the end of the summer season.
The mall in Bolingbrook has a really cool fountain of spinning solid granite balls that you can push with your hand, and I assume those too go away for the winter, though they must be difficult to move, being both fragile and heavy.