Abstract: A weighted medical blanket is provided for containing a polymer gel; the device of the invention maintains consistent weight over time and can be warmed or cooled to be applied to patients to provide heating or cooling and can be easily cleaned, reused, and its weight reconstituted through the insertion of water through an insertion valve and insertion sleeve suited to reduce flow out of the device. Disclosed is a method for alleviating post-operative shivering utilizing the device of the invention.