Life support systems, also known as life support, was technology which assisted lifeforms in surviving.
Spacecraft had life support systems which allowed its occupants to survive in space. (TV: The Ambassadors of Death, Colony in Space, Four to Doomsday, Terror of the Vervoids, The Tsuranga Conundrum) TARDISes also had life support systems, (PROSE: The Edge of Destruction, Timewyrm: Genesys, Flatline) as did miniscopes. (TV: Carnival of Monsters)
Some individuals had life support systems to compensate for what would otherwise be fatal injuries. On Skaro, Davros was given a life support system after being crippled. Later, the Kaleds built a combination life support system and travel machine for the creatures they knew would evolve into. (TV: Genesis of the Daleks) On Karfel, Renis' wife was on a life support system in a hospital. (TV: Timelash) On Sto, Max Capricorn's cybernetic body functioned as a life support system. (TV: Voyage of the Damned) Hydroflax's robot body was a life support system. (TV: The Husbands of River Song) Ianto Jones took parts from a cyber-conversion unit and modified them into a life support for Lisa Hallett. (TV: Cyberwoman)