Suspended Animation

Cryonics is the low-level temperature preservation of humans and animals in a suspended animation by slowing their vital functions, for the purposes of preserving them and keeping them alive for periods of time ranging from decades or even centuries until they are needed. Other purposes include safekeeping, or for keeping them alive for as long as possible while their brains are connected to an external expression device.

History
Before the Great War, Robert House and his company, as well as the Big Mountain Research Facility, are known to have produced technology within the cryogenic and cryonic field. Robert House extensively researched extending the human life, and created his own cryonic chamber that allowed the user to connect their brain pattern and consciousness to an external interface. Big Mountain produced hibernation chambers with similar purposes, however, the nature of their research into the field is unknown. The United States Armed Forces experimented with cryonic technology as well, making the systems at the Raven Rock facility, and using cryonic chambers in the Sierra Army Depot.

Fallout 2
The Sierra Army Depot dealt in the field of cryonics, with one example being their cryonic submergence of Dobbs in bio med gel. The Environmental Protection Agency utilized the use of hibernation chambers, holding three subjects within each. These editions were large transparent tanks filled with ice cold water, that is filled and drained through a long serpentine pipe system.

Fallout 3
The Enclave's scientific personnel at the Raven Rock base in the Capital Wasteland have several rooms dedicated to stasis, and their prisoner restraints use the same systems. There are two different versions of the Raven Rock stasis chambers: a green chamber holding the subject in the center, and a transparent blue holographic/light-based/photonic resonance chamber. The systems in Raven Rock appear to be the most advanced systems of their kind currently known on Earth. These chambers have been used to preserve yao guai, deathclaws, super mutants, feral ghouls, and human prisoners. Whether these stasis chambers are built for long-term preservation on the scale of years is unknown. The same blue-light stasis technology is used in Fort Constantine's T-51b power armor storage room, as well as the hazmat testing ground in the Big Empty, for storing the hazmat suit. Although unseen in-game, Vault 87 was meant to have been equipped with four stasis-chambers.

Its history unknown, a liquid nitrogen-based weapon commonly known as a cryolator could be easily constructed.

Mothership Zeta
The alien civilization aboard Mothership Zeta made cryonics a core aspect of their invasion and their research. The longest known preservation of a subject aboard the ship was over 600 years. They worked by entirely sealing the subject and the chamber from the outside, and used freezing cold air to suspend the subject. When opening, the chamber would decompress and stabilize with outside air, and force the subject to drop to the floor. Furthermore, there was a second method of cryonics used by the aliens. In their dedicated cryo lab, during the Zeta Uprising, the Lone Wanderer could have frozen alien soldiers with the loose systems, thawing them into an ice block for a mere few seconds. Elliott Tercorien could have harnessed the energy to create cryo grenades and cryo mines, which exact the same effect on targets within the blast radius.

Fallout: New Vegas
The only instance of cryonic technology in the game is Robert House's cryonic preservation chamber in the Lucky 38. This is one of the only known instances of a cryonic chamber that links the subject's brain and consciousness with an external interface. It is a fairly unadvanced piece of technology, even for House and RobCo's expertise, since it has barely preserved his body for the two-hundred years he has inhabited the chamber. House's body is extremely physically decrepit and can only live inside the chamber. Opening the chamber, even for a second, will doom the subject to having only little more than a year left at life due to exposure to outside contaminants. House hopes that with the Courier's help, he will be able to make the same cryonic technology he uses available to other high-value individuals in the future.

Fallout 4
According to GameInformer, Vault 111, located in Boston, has at least one cryosleep pod.

Fallout Tactics
Vault 0 kept pre-War geniuses in cryogenic stasis, by extracting their brains from their body and freezing them. They were then hooked up to the Calculator supercomputer, melding all of the identities of each connected brain into one.

Van Buren
The Boulder Dome in Denver was equipped with prototype military medical cryo tanks that had a very high malfunction rate, and before the Great War, scientists were frozen in sleeper tanks. Victor Presper continued to use the equipment during his time spent there.

Appearances
Cryonic technology appears in Fallout 2, Fallout 3, its add-on Mothership Zeta, Fallout: New Vegas and its add-on Old World Blues, Fallout 4, and Fallout Tactics. It is also mentioned in the Fallout: New Vegas add-on Dead Money. Cryonic technology was also meant to appear in the canceled Van Buren.