A system for controllably turning over a patient in a bed includes a flexible body sling and a ratchet device. The flexible body sling includes a main torso portion that terminates in a first end and an opposing second end and is configured for placement under the patient between a head and a tailbone of the patient. The flexible sling has a first sling strap that is coupled to the first end and a second sling strap that is coupled to the second end. The ratchet device has a mount that includes a curved portion for placement over a side rail of the bed to detachably secure the ratchet device to the bed. The ratchet device has a rotatable spool with a slot for receiving one of the first sling strap and the second sling strap. The ratchet device has a pivotable handle for driving the rotatable spool.