Abstract: Therapeutic devices for warming and/or cooling limbs, joints, and body parts, to relieve pain or discomfort, are made of entirely hypo-allergenic materials, such as organically grown cotton fabric and flaxseed. Flaxseed can be heated effectively and safely in a microwave oven, and has a relatively high “specific heat”, allowing it to impart a sustained therapeutic benefit. A suitable quantity of flaxseed is loaded into an envelope or bag, leaving sufficient room to allow the bag to be bent, twisted, wrapped, or draped in a comfortable manner, around a limb, joint, neck, etc. These devices are suited for use by people who suffer from chemical hyper-sensitivity, allergic syndromes, or immune-related problems, and they can reduce the risk that a person who frequently needs comfort for a chronically painful or uncomfortable body part might create or aggravate an allergic reaction or hyper-sensitivity problem.