Vessel:       vertical dewar, vacuum-jacketed
Contents:     liquid nitrogen, −196 °C
Occupants:    4 whole-body, inverted;
              5 neuro, upper canister
Orientation:  head-down (see note)
Consumption:  ~10 L/day, gravity-fed top-up
Note:         inverted so that on loss of
              coolant the head warms last.
Staff:        2 on site
Ambient:      22 °C, light-industrial unit
Adjacent:     a firm that resurfaces bowling lanes

The detail that undoes people is not the nitrogen. It is head-down, and the reasoning behind it, which is impeccable, and which requires someone to have sat in a meeting and worked out the failure mode and specified the orientation accordingly.

This is a mortuary practice of extraordinary sophistication and it is not, structurally, distinguishable from natron and linen and a canopic jar for the liver. The Egyptians also had a technical literature, a professional class, a contract, and a defensible theory about what part had to be preserved for the person to resume.

Their theory was wrong in an interesting way. It located the person in an organ. Ours locates the person in a pattern, and preserves the substrate the pattern last ran on, at ten litres a day, next to a bowling-lane resurfacer, in a light-industrial unit, in the desert, indefinitely.