A few keys within Call of Duty DMZ are incredibly difficult to find the location of, and a terrific example of this is the Rusted Fridge key. Players can find this key just like most others in DMZ, through random chance, but using it is a whole other monster. Players will likely not find the location of this key by searching all of the major points of interest on Ashika Island.
As a result, players will either grow frustrated with the Rusted Fridge key or simply toss it in their key stash to be forgotten. To score the loot from the Rusted Fridge key, players will need to travel to a location on Ashika Island that is rarely visited.
Before dropping into a DMZ match on Ashika Island, make sure that you have taken the Rusted Fridge key out of your key stash and put it into your inventory. With the key in hand, drop onto Ashika Island and then make your way to the very southernmost point of the map.
More specifically, you want to head to the small circular location in the middle of the ocean to the right of the Beach Club. You can see precisely where this is in the map screenshot below.
You can get to this location by swimming to it or using the bridge that connects to the island. Either way, go to the very back of the deck that goes around the circular building. Look on the ground for a rope and once you find it, hop on the guard rail that faces the ocean and look down.
You should see a crate with a white outline at the bottom of the water. Jump into the water, swim to the crate, and you will be prompted to use the Rusted Fridge key.
