This study aims to examine the effect of hot compress applied with Nigella sativa (black cumin) and Zingiber officinale (ginger) essential oils on pain, morning stiffness, physical function, and patient satisfaction in individuals with knee osteoarthritis. The study is planned as a randomized controlled experimental study with 120 participants. Inclusion criteria: aged 18 and over, diagnosed with knee OA, Kellgren-Lawrence stage 3, VAS pain score ≥4, no known allergy to the essential oils, no open wound on the knee/foot, no knee surgery, not receiving any other alternative treatment during the study period, and not pregnant. Participants will be randomly assigned to four groups (30 each): 1) ginger oil + hot compress, 2) black cumin oil + hot compress, 3) sham (hot compress only), 4) control (routine treatment only). Data collection tools: Patient Information Form, WOMAC, VAS-pain, VAS-satisfaction. Applications will be performed once daily for 7 days (30 minutes per session). Assessments will be conducted at baseline and on day 7.