Flame jets are fire-spewing devices found in Magmoor Caverns. They are possibly a part of some form of exhaust system in the Caverns. Some constantly spew fire, while others will turn on and off at intervals. They can be frozen with the Ice Beam, rendering them useless for some time. Their name originates from concept art of the game. They are only found in Pit Tunnel, Fiery Shores, Lake Tunnel, South Core Tunnel and Transport Tunnel C.
Metroid Prime and Metroid Fusion: Prima's Official Strategy Guide refers to them as "flame geysers".
In Metroid Dread, one room in Artaria features flame jets along a shaft lined with blue magnetic strips. Samus must use the Spider Magnet to carefully climb the shaft while jumping back and forth between walls as the jets activate. There is also a room in Cataris lined with flame jets. These jets cease to hurt Samus after she acquires the Gravity Suit, but other forms of fire remain harmful to her.