The first generation of hot compress sea salt, the second generation of hot compress sea salt: In order to prolong the service life, Taiwan Province bag salt field has been studied for four years, published in 1998. Because it can be used for 10 to 15 days, I applied for a patent. This is indigo salt sold in pharmacies, also called halite. Of course, there are many names. Drug stores are all 10 yuan a kilo. The disadvantage is that pepper is still needed to promote the absorption of meridians. Third-generation hot compress sea salt: it came out in 2004, and it has the characteristics of high temperature and no melting, and the effective minerals are evenly muddy. The service time of sea salt for frying is extended to 1 month, and the service time of sea salt for microwave oven can reach 4 to 5 years. Later, the popular "ice and fire physiotherapy pillow" belongs to this type. The advantage is that compared with the second generation of sea salt, the gynecological treatment time is shortened to 2 years, and the previous sea salt needs about 3 years. The fourth generation of hot compress sea salt, its efficacy is 30 times that of the third generation sea salt, and it can be used repeatedly for 4 years, shortening the time for treating gynecological diseases. It has the advantages of uniform drug release, no melting at high temperature and high mineral enrichment. The disadvantage is that it can only be heated by microwave oven. There are relatively many varieties.