Cold compresses are applied to the sprain for a minimum of 48 hours, and can be extended to 72 hours if the patient can tolerate the cold. After a sprain occurs, there is local edema, pain, and limited movement. Mild cases require cold compresses for 4 hours to relieve the swelling and pain, while severe cases require cold compresses for more than 48 hours to bring the symptoms under control and allow the patient to resume normal life and work. Cold compresses for 48 hours are required to significantly inhibit the increase in vascular permeability and reduce tissue interstitial exudation. If the cold compress is applied for only 24 hours, the swelling will reappear after the cold compress is no longer applied, and it will be progressively aggravated, which is not conducive to the repair of damaged tissues and will affect the prognosis.