Every non-invasive body contouring system relies on one fundamental principle: heat changes tissue. At the right temperature, radiofrequency (RF) can tighten skin by stimulating collagen remodeling, increase circulation, and even trigger apoptosis in subcutaneous fat cells. But heat also carries risk. A difference of just 1–2 degrees Celsius can determine whether the tissue undergoes productive remodeling or crosses into the territory of thermal injury.