You can use hot salt packs to apply local heat during menstruation in the following cases: 1. If you have lower abdominal pain during menstruation, you can use hot salt packs to promote blood circulation, make menstrual blood flow more smoothly, and improve the symptoms of lower abdominal pain. 2. 4.If there is discomfort and fatigue in the lower abdomen during menstruation, you can also use the method of hot compress salt bag to give the corresponding improvement. In the menstrual period to pay attention to keep warm and preferably do not drink frozen drinks, so as not to cause pain in the lower abdomen.