Items freeze when on top of something cold

Items should freeze when on top of snow, snow layers, ice, powdered snow, etc. this would keep the item from despawning and make a cool ice texture around it. If the item is moved onto something hotter then it will unfreeze in 10 seconds or so it will take about the same amount of time to freeze in the first place. This could be an incentive to live in the new mountains because your stuff will no longer despawn when you die. Also it could be used in things like display cases so you can show off your items. Frozen items should not be able to go into a hopper.