The materials needed for the coarse salt package are very simple, one towel and two Jin of coarse salt. First, take a towel and fold it in half, sew up the three sides and leave a hole. It is best to sew carefully to prevent coarse salt particles from leaking out. Pour the bought crude salt into the pot and stir-fry, then pour the crude salt into the towel from the reserved hole and sew the hole. In this way, the coarse salt package is ready. Put the prepared coarse salt bag on the painful and cold-resistant joint. Hot compress 15 ~ 20 minutes each time until the original salt is gradually cooled. If the temperature of hot compress is very high, you can put a towel on the affected area to avoid burns. In addition, the hot pack can be reused and heated by microwave oven. This method can quickly relieve joint pain and persist for a period of time, which can obviously improve symptoms. But it cannot be used for arthritis patients with swelling and inflammation.