> there's a store running a giant AC on full blast with the doors wide open Despite the apparent vulgarity of this, usually they have some sort of air-curtain

> there's a store running a giant AC on full blast with the doors wide open Despite the apparent vulgarity of this, usually they have some sort of air-curtain system installed (that fan that blows a wall-of-air at you when you step through the doorway) to keep bugs out and create a crude temperature buffer between the outside and inside. Bizarrely, this does have the effect of keeping the chilled air inside the building.