Well, Hell must have frozen over. I'm taking the side of a public sector union.
This is dumb. A prisoner could rape or murder a guard and there would be no real punishment for the crime -- especially if the prisoner is already serving a life sentence.
This push isn't against old, American cases like Henri Young (which the movie Murder in the First butchered in terms of historical accuracy) in which he was held in solitary for three years before murdering a fellow inmate, and Young's defense argued insanity due to the extended time in solitary.
This would make the worst thing that can happen to the worst prisoners who decide to do the worst things in prison a four hour time-out with periodic wellness checks.
That's not a deterrent.