Should a sprain be treated with heat or cold therapy?

Whether to apply heat or cold depends entirely on the clinical situation.

1. Cold therapy is primarily used for pain relief. In cases of acute injuries—such as ankle sprains, knee twists, muscle strains, or contusions—the onset of pain and swelling is typically immediate. Immediate application of cold therapy provides analgesic and local anesthetic effects. Within the first 24 hours following an ankle sprain—the acute phase of injury—cold therapy is recommended. It reduces local blood flow, inhibits swelling, and alleviates pain. Conversely, applying heat during this period causes vasodilation, increases local blood flow, raises tissue temperature, and thereby exacerbates both pain and swelling. Similarly, topical agents such as alcohol-based rubs, safflower oil, or medicated plasters produce a warming effect; therefore, these should be avoided during the initial phase of injury.

2. Heat therapy promotes healing. After 48 hours post-joint sprain—and provided there is no ongoing bleeding or active swelling—heat therapy may be applied to accelerate resolution of edema and relieve pain. Methods include warm, moist towels, hot water bottles, or warmed hard-boiled eggs placed over the affected area. This elevates local tissue temperature, enhances blood circulation and local metabolism, and facilitates absorption of hematoma and exudate—thereby promoting faster resolution of swelling and wound healing. Additionally, heat therapy improves soft-tissue elasticity, helps prevent joint stiffness and muscle spasm, and further relieves pain.