What constitutes cruel and unusual punishment?

Here we are not considering ad hoc response to an emergency, but a penological policy of punishing harshly the disruptive conduct of a prisoner. The kind of measures used--serving unpalatable food, denying outside exercise, using shackles in the shower and full restraints in the cell, keeping the person naked in the cell, isolating the prisoner in a special sound-proofed and constantly lighted cell--are measures correctly described as conditions of prison life for this prisoner and for other prisoners similarly situated. Each of these measures involves the infliction of pain under the standard set by Jordan v. Gardner, supra at 1526. Each of the measures may, depending on the finding of the district court, involve deliberate indifference on the part of the prison officials and so constitute cruel and unusual punishment. Id. at 1528.