When Kylo Ren becomes enraged- destroying expensive equipment and killing random stormtroopers- Hux (or Phasma) take it upon themselves to forcibly take him to his own special room in the medical bay. There, they lock Ren up in some type of full-body bondage contraption/bed until he calms down. Maybe sedating drugs have to be used as well if he's being particularly violent or resisting.

+ For degrading or humiliating talk towards Ren during this.
++ For Ren eventually calming down, falling asleep, etc.