Heat dilates blood vessels, which improves circulation around the knee joint. Better blood flow delivers more oxygen and nutrients to tissues, speeding up recovery and reducing stiffness.

Warmth softens the surrounding muscles, tendons, and ligaments. This helps reduce the tension that often causes pain or restricts movement.

While cold therapy is used for fresh injuries, heat is ideal for chronic pain — it helps relax inflammation-related tension and improves comfort for conditions like arthritis or stiffness from overuse.