The Insulated Pack is a backpack from the Reign of Giants DLC, used to expand the character's inventory. While it has only 6 inventory slots, perishable items contained within will spoil two times slower (same as Ice Box). It requires 1 Thick Fur, 3 Gears, and 3 Electrical Doodad to craft and an Alchemy Engine to prototype.
The Pack itself cannot be placed in one's inventory or a Chest and only one may be equipped at a time. When an Insulated Pack is created, it automatically equips itself in the Chest Slot, if it is available. This item uses the same equipment slot as Armor and Vests, which means wearing one requires sacrificing the benefits of the other.
Although Insulated Packs cannot be placed in inventory or in Chests, they can be placed on the ground and used for storage. Any item clicked on an Insulated Pack which is on the ground will give the 'Store' option allowing the pack to be filled without equipping it.
Despite slowing the spoilage of food items, the Insulated Pack does not completely work the same way as an Ice Box. Unlike the Box, the Pack will not stop the spoilage of Ice and Ice Cubes and will not be able to freeze a Thermal Stone. Additionally, it will completely prevent hot food from cooling off over time.
Care should be taken around fire as the Insulated Pack is flammable, and will drop all of its contents if incinerated completely.