Environmental engineering
Environmental engineering (or life support center) was a section aboard  starships where all life support activities on the ship were controlled and monitored. This section was located in the primary hull.

In 2266, Bobby climbed a ladder into a shaft labeled "environmental engineering personnel only". () Later that year, the Psi 2000 virus infected Hikaru Sulu climbed up a same shaft with the same labeling, while carrying a rapier. () Some time later, that year, Leonard McCoy stood in front of a similar sign. ()

In 2268, when the Scalosians took over the , they installed a deep-freeze device in environmental engineering with the intention of putting the entire crew into suspended animation. ()

In the alternate reality, this center was located (in the) aft of the warp nacelles. In 2259, during negotiations to return his crew to him,  threatened to destroy this center if his request was denied. ()

See also
Life support control
Spacecraft sections