FUD Cryo

A cryo-chamber aboard the UNSC Forward Unto Dawn.

A cryo-chamber is a plastasteel[1] chamber that allows all of a starship's non-essential personnel to be cryonically frozen for long periods of time. An example of its use would be during prolonged Slipspace jumps. They are basically large metal pods with form-fitting gel beds where the personnel are frozen until they are needed. An example of this is John-117, who was stored in a cryo-chamber aboard the ship UNSC Pillar of Autumn and later unhatched from the cryosleep chamber by Tech Chief Thom Shephard along with Tech Officer Sam Marcus.

Known models of the cryo-chamber include the Mark VII Personal Suspension Unit, manufactured by Jakubaitis Standard Systems. It was widely disliked by UNSC personnel because of its inferior moisture balancing; this resulted in dry, itchy skin for a day or more after awakening, known as "cryo-itch." It was later replaced by the Mark VIII Cryogenic Suspension Chamber, although many older craft still use the Mark VII.[2]

Technical SpecificationsEdit


A standard cryo-tube aboard a Halcyon-class light cruiser.

The cryo-chambers are usually stored in their own areas of the ship. Each cryo-chamber will hold an individual for as long as necessary, provided they use a Bronchial Surfactant, and can be ejected prior to an emergency landing, thus saving some crew from harm to be recovered later. Spartan-058, after being severely injured during the fall of Reach, was placed in a cryo-chamber in the UNSC Pillar of Autumn. Prior to the ship's landing on Installation 04, her cryo-chamber was ejected, and she was picked up by John-117 at a later date.

Cryo-chambers are monitored by the ship's AI, and the AI can awaken crew members at a moment's notice. The cryo-chamber's control computer is designed to change the dosage of necessary medications, or modulate the internal temperature, if an individual appears as though they might wake from cryonic sleep.[3] Cryo wake-up protocols demand that crew check each other to make sure everyone revives from cryo all right. There is usually a medical pod in cryogenics bays for emergency resuscitation situations. People are almost always stored in cryo-pods naked, as covered tissue rapidly becomes damaged due to intracellular ice crystal formation, a condition commonly known as Freezer burn.[4] Contrary to normal protocol, however, in Halo: Combat Evolved, John-117 emerges from the cryo-chamber completely fitted in his armor, using Spartan training to ignore the pain. His enhanced physiology presumably allows for a quick recovery from superficial pain and injury such as this.[5]

After the Battle of Installation 00, after the Arbiter flies the front half of the UNSC Forward Unto Dawn through the Ark Portal, the back section with John 117 and Cortana remain behind. Cortana sends out a signal, but it takes years for it to reach the UNSC. Recognizing the possibility of a large wait time, John goes into cryo sleep until someone finds him. He is awoken by Cortana almost 5 years later after a Covenant fleet boards and ransacks the Forward Unto Dawn.

Trivia Edit


Cryo-chambers aboard UNSC Spirit of Fire, as seen in Halo Wars.

  • Cryo-chambers are referred to as "the freezer" in slang,[6] named after a term often called freezer burn, which is a painful condition caused by frozen liquids damaging cells, organs, and joints. Another slang term for the chamber is "the Admiral's wife" because it is a "frosty bed."[7] Being put in cryo is also referred to as being "put on ice."[8]
  • The Slipspace Field Pod is the Forerunner equivalent to the cryo-chamber.
  • While in cryo, humans don't age due to nearly halted metabolism. Individuals in cryo tubes are given a steady supply of pharmaceuticals that control the frequency and duration of cryo-sleep cycles along with influencing the content of their dreams.[9]
  • Even though humans must enter a cryo-tube naked or risk being blistered when they emerge, Professor Ellen Anders entered her tube with her clothes on.
    • This was also done in Halo 4: Forward Unto Dawn, where the cadets must enter cryo-sleep to overcome the side effects through training. They use what appear to be special suits in order to remedy the freezer burn experienced under normal circumstances.
    • Master Chief also enters cryo-sleep in his suit in all appearances.
  • In Halo: Combat Evolved, it is possible through a glitch to get back inside, and see John, headless.
  • In the Halo Legends episode The Package, when John-117 locates Dr. Catherine Halsey in a cryo chamber, she is fully clothed. Yet when she awakens she appears to have not suffered any effects of freezer burn such as any visible rashes or blisters nor does she show any signs of pain or discomfort.
  • A cryo-chamber is available as an avatar prop with the Halo 4 Limited Edition.
  • There is a Mega Bloks Edition set that is a UNSC Cryo Bay with John-117 and Cortana.




  1. Halo: First Strike, page 150 ("John brushed off the frost buildup that clouded the top half of the cryotube, and revealed the green-armored figure sprawled behind the plastasteel shell.")
  2. Halo Encyclopedia, page 216
  3. Halo: Contact Harvest, page 60 ("The cryo-computer observed a surge of activity in Avery’s brain-an effort to yank himself out of REM-and upped his dosage.")
  4. Halo: The Flood, page 20
  5. Halo: The Flood, page 21
  6. Halo: The Fall of Reach, page 102
  7. Halo: The Cole Protocol, page 21
  8. Halo: The Cole Protocol, page 21
  9. Halo: Contact Harvest, page 60