Cryotherapy (the use of ice and exercise to rehabilitate athletic injuries) can be an effective method of treating baseball injuries. It is generally agreed that ice is appropriate for the first 24 to 48 hours, but there is disagreement over its use beyond 72 hours. Some physicians and trainers support the use of heat with either exercise or rest, believing that this increases the effectiveness of the healing process and reduces the time involved. Due to the way that muscles heal, however, and the characteristics of collagen (a protein crucial to the healing process), cryotherapy can be a more effective treatment, reducing the healing time and the risk of reinjury. Ice can be applied either with an ice bag, an ice massage, or an ice water submergence. If pain or swelling persists beyond 72 hours, the advice of a physician should be sought. (DC)