Place the darker side of the heat cells against your skin. The product may not warm up as efficiently if you put the wrong side against the skin.
Remove the peel paper from the adhesive tabs. Bend knee (or elbow) slightly and place opening over kneecap (or elbow). Press the adhesive tabs onto your skin. Wrap straps around knee (elbow) and fasten.
Note: Do not place heat cells on the back of the knee or inside the bend of the arm.