This section of the space station is meant to simulate icy sub-zero environments, such as arctic or tundra. Without the Varia Suit, it is impossible for Samus to explore this sector, due to her newly-gained vulnerability to cold.
Samus unlocks Yellow Hatches here. Both Ice Missiles and Power Bombs are acquired here, by means of downloading. After the Power Bomb, Samus encounters the SA-X, nearly chasing Samus through half of the Sector. She later faces Nightmare in the electronic junkyard here, but this is only after it has broken free, destroyed nearly all of the sector, and melted most of the ice. Samus is assigned to neutralize it due to the threat it presents to the rest of the station. After its defeat, Samus recovers the Gravity Suit.
- Aqua Zebesian
- Blue X
- Fake tank
- X Parasite
Although this sector's main theme is Sector 5 (ARC) Low-Temperature Zone Area, Facing a Huge Reaction plays in it a total of three times: on her first visit to Sector 5 until she reaches the first frozen room, after exploring the Habitation Deck and returning here to use the Data Room, and after defeating Nightmare. The latter instance is the last time the theme is heard in the game, and it continues until Samus reaches the aquatic portion of Sector 4.
"This sector is used to research creatures living in extremely cold habitats."
"The arctic sector is filled with organisms that thrive in sub-zero temperatures."
- Unlike other Sectors, which are visited twice, Sector 5 is visited three times: once to acquire Ice Missiles, again to return to the Data Room and gain Power Bombs, and finally, to deal with Nightmare.
- This is the only Sector that contains Yellow Hatches. This may be extra security for Nightmare. It could also be attributed to the fact that this is the last Sector that Samus goes to explore (when the game is introducing the six areas).
- The icy rooms in Sector 5 deal far more damage than the Sub-Zero Containment does before Samus acquires the Varia Suit, likely for difficulty balancing purposes and to discourage early exploration.