A rectangular metal sign with sharp, angular edges, featuring a bold, high-contrast design typical of brutalist architecture. The sign is predominantly matte black with a bright, luminous orange border and central iconography depicting a stylized thermometer with extreme high and low temperature indicators. The surface has a slightly weathered texture, with subtle scratches and dents suggesting frequent use in harsh environments. The text 'EXTREME TEMPERATURE ZONE' is embossed in a clean, sans-serif font, with the letters slightly raised for tactile emphasis.