If an unstable spinal column injury is moved, damage may occur to the spinal cord. Between 3 and 25% of SCIs occur not at the time of the initial trauma but later during treatment or transport. While some of this is due to the nature of the injury itself, particularly in the case of multiple or massive trauma, some of it reflects the failure to adequately restrict motion of the spine. SCI can impair the body's ability to keep warm, so warming blankets may be needed.