He 'kept/maintained his cool' [=he didn't get angry or upset] even though it was clear that he was being unfairly treated.
He was struggling to 'maintain his cool/composure'. [=he was struggling not to become angry or upset]
They barely had enough food to 'maintain life'. [=to make it possible for life to exist or continue]
(..) How the fuck are you going to jail tomorrow. Prison. Not jail. You're missing my shower. Polly I'm really sorry. I know. You focus on how you're going to maintain your eyebrows behind bars. You may not come back with a unibrow. Am I allowed to cry? No. Seriously. No. (..)2013 TvShow: Orange Is the New Black Title: I Wasn't Ready Season: 1 Episode 1