The article doesn't make it clear, but what heat really destroys is, specifically, a type of long-range entanglement between electrons. Heat makes entanglement

The article doesn't make it clear, but what heat really destroys is, specifically, a type of long-range entanglement between electrons. Heat makes entanglement with containers greater, and entanglement with nearby particles is unavoidable. A very hot cube of metal isolated in a vacuum wouldn't have any less overall entanglement than a cold cube.