Add subtle frostbite effects to the face only. Keep the exact same face shape, eyes, mouth, proportions, line thickness, and background. Do not move, resize, or redesign any elements. Only add minimal icy texture and light blue frost cracks on the cheeks and forehead. Slightly cool the face color tone. No glow, no extra shading, no new details, no background changes.Do NOT add any circular border, outline, stroke, edge, or enclosing shape of any kind. Do NOT redraw or re-vectorize the face shape. Keep the face open with no boundary. Apply frostbite effects only to the existing facial features. Preserve the exact eyes, mouth, proportions, and background. No new shapes, no outlines, no borders, no frame.