How to complete Freezer Burn and slow Hellhounds in MW3 Zombies

The main story of Call of Duty: Modern Warfare 3’s Zombies mode has you working through three acts, comprised of several challenges and unique tasks that grant experience and special rewards. One of these challenges is called Freezer Burn, which is included in tier three of Act One.

The challenge for Freezer Burn can be difficult to complete, but it will reward you with a unique Baseball Fan calling card as well as 1,500 XP.

Here’s what you need to know about how to complete Freezer Burn and slow Hellhounds in Modern Warfare 3’s Zombies.

How to complete the Freezer Burn challenge in MW3 Zombies

To complete Freezer Burn, you’ll need to slow 50 zombies and 10 Hellhounds using a weapon with the Cryo Freeze ammo mod.

The Cryo Freeze ammo mod is a mod that you can add to any weapon you find while playing MW3 Zombies, which gives your shots a chance to freeze your targets.

How to slow zombies and Hellhounds with Cryo Freeze in MW3 Zombies

With the Cryo Freeze mod equipped on a weapon, your shots will have a chance to slow zombies. While Cryo Freeze is equipped, you’ll have to hit body shots and fully wait for the freezing effect to take place in order to get credited for “slowing” a zombie.

While you can slow zombies at any threat level, you will have to go to medium or high threat to slow Hellhounds, since level one Hellhounds will die from just one bullet in low threat zones. Even if you have Cryo Freeze, you won’t get credit for killing level one Hellhounds with one bullet if they’re not slowed.

All rewards for completing the Freezer Burn challenge in MW3 Zombies

If you get the Cryo Freeze ammo mod and slow the requisite 50 zombies and 10 hellhounds, you’ll be rewarded with the following:

• 1,500 XP

How to get the Cryo Freeze Ammo Mod in MW3 Zombies

There are a number of places that give you a chance at picking up Cryo Freeze. There’s a chance you might loot it from large Aether Caches you find while searching and clearing Aether Nests, Infected Strongholds, or Mercenary Strongholds.

You can also earn the Cryo Freeze ammo mod by completing any of the contracts you find in Zombies and looting from the rewards rift that appears. Like the Aether Caches, it’s not guaranteed, but that only means you’ll have to complete more than one for Cryo Freeze to finally appear.

Another option is to seek out the Elemental Pop machines. These do provide a random elemental effect, so there’s a good chance you might not get it. These are also much more costly and are not at the top of my list for you to try.

Finally, if you happen to find and extract the rare Cryo Freeze ammo mod schematic, you can spawn into any match with the Cryo Freeze ammo mod ready to go.