With polyimide coatings or high-temperature acrylates, some cables withstand 300°C long-term and tolerate spikes to 490°C. Polyimide enables ~300°C. Most standard optical fibers operate reliably down to -40°C, but temperatures below this threshold cause significant performance degradation: Silica glass—the core material of optical fiber—has an extremely low thermal expansion coefficient (≈0. 5×10⁻⁶/°C), meaning it barely shrinks or expands with. High-temperature resistant fiber optic cables use advanced coatings like (Polyimide coating properties and temperature ratings for optical fibers) 1, silicone, or high-temperature acrylates. They also employ hermetic and fused silica fibers. These materials tolerate prolonged heat. In fact PCA's CAT 6A 10G XE UTP cable will work optimally unless if it is in weather over 167 degrees Fahrenheit (75°C), which is 33. 9 degrees Fahrenheit hotter than the hottest recorded temperature on Earth, which was 134.
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