Amends the Unified Code of Corrections. Provides that a minor placed in a State or county juvenile detention facility may not be placed in isolation for discipline, punishment, retaliation, or any other reason except as a temporary response to a minor's behavior that poses a serious and immediate risk of physical harm to any individual, including the minor. Provides that if a minor placed in a State or county juvenile detention facility poses a serious and immediate risk of physical harm to any individual, including the minor, before a staff member of the facility places the minor in isolation, the staff member shall attempt to use other less restrictive options, unless attempting those options poses a threat to the safety or security of any minor or staff. Limits the amount of time the minor may be placed in isolation. Amends the Juvenile Court Act of 1987 to make conforming changes.