Abstract: A thermal pack having a high heat-retention character which may be quickly heated or chilled consisting of an absorbent package having a gel-forming synthetic organic resin in particulate form deposited on an adhesive-coated substrate disposed between a pair of fibrous non-woven porous filter layers and covered on the outside by a pair of paper-like plies of non-woven porous absorbent material. The outside covers are seamed together around their periphery to form a closed envelope.The thermal pack of the present invention may be positioned in a pouch which is adapted to be held in place over the afflicted area of the body by releasable fastening means. The pack and pouch are formed of porous material which is capable of being heated in microwave oven or cooled in a freezer.