1, only when the foot is just sprained, usually within 24 hours (some say 48 hours) cold compresses to reduce the swelling of the affected limb. 2.After the swelling subsides later, you can apply moderate hot compresses to increase local blood circulation. 3.But there is a condition that cannot be compressed with heat, that is, the ankle is obviously swollen and stiff. In this case, you need to exercise the ankle function and apply ice packs for 5-10 minutes after 30 minutes of exercise. 4. If you have the condition, take an MRI to see the level of ankle ligament damage, which ligament is the most serious, and then treat it symptomatically.