[Passive] You cannot suffer starvation or exhaustion, so you do not need to sleep or eat. However, you must spend 1 supply for every 2 points of Stamina you wish to recover when you recuperate. Once every 24 hours, you can spend 1 hour reflecting on your past experiences to gain XP without sleeping, following the normal rules for gaining XP while sleeping.
[Passive] You do not need to breath and suffer no ill effects from poisonous gas.