Subject: That's what disguises are for.
Author:
Posted on: 2011-09-26 11:00:00 UTC
Remember that the Disguise Generator built into the console morphs the entire physiology of the Agent using it (except the brain).
So, any kind of device needed to keep an Agent alive in "normal" conditions would be either disguised alongside the Agent himself or made redundant until the mission is over. Probably both.
Be sure of playing the fun out of it! Agent A forcefully removing the gas mask from Agent B in order to make him realize that thanks to the disguise he can breathe normally (and B panicking until that dawns on him) has a lot of comedy potential.