These cables, also known as Circuit Integrity Cables, are designed to withstand high temperatures for a certain minimum period under direct fire. These cables are useful to maintain circuit integrity during the defined period of fire, and their construction differs from that of ordinary cables. The conductor is manufactured with specially designed heat barriers and fire-resistant insulation, preventing fire from reaching the conductor surface. These cables operate at high temperatures of up to 650°C, 750°C, and 950°C, depending on various operational conditions and applications. They are commonly used in power stations, mass transit underground passenger systems, airports, petrochemical plants, hotels, hospitals, and high-rise buildings.