2. Find a clean, oil-free, water-free and tasteless bottle, put ginger slices in it, and add a proper amount of white vinegar, which is better than ginger slices.

3. Seal the bottle and put it in the refrigerator 15 days.

4. Take out the ginger slices and apply them to the spots. You can rub them gently back and forth until you feel a fever, so you can stop. Then clean the wiping area with clean water.