Cold therapy after vaginal birth helps reduce perineal swelling and pain by causing blood vessels to constrict, which limits fluid leakage into tissues and speeds initial comfort during healing. The most swelling and discomfort happen in the first 12 to 24 hours after delivery, so applying ice in that window targets the peak edema and provides the most relief. Typically, a cold pack is used for about 15 to 20 minutes at a time, with at least an hour between applications, and the ice should be wrapped to protect the skin. After the first day, cold is often used as needed, but the strongest benefit comes from addressing the swelling early on and then transitioning to other comfort measures as healing progresses. This approach is especially helpful with perineal trauma such as lacerations or an episiotomy, aiding overall comfort during the immediate postpartum period.