Why is there water in the electric salt hot compress bag?

Sea salt hot compress water is caused by a small amount of salt infiltrating into subcutaneous tissue through the body surface. During the hot compress of sea salt, high temperature will expand the sweat pores of the skin, and some salt will enter the lower tissues of the body surface. Sea salt is rich in Na ions and Cl- ions, so a temporary high osmotic pressure area will be formed in the hot compress area. Tissue fluid and intracellular fluid are collectively referred to as body fluid, which flows to the high pressure area, causing local water filling and even overflowing with the expanded sweat pores. But it's only a small part. Don't worry too much. The body has a certain function of self-regulation and maintaining internal environment stability.