Firmware & throttling: Where available, use module or switch firmware features that reduce power (and heat) under thermal stress. Prevent hot spots: Avoid placing heat-generating equipment directly above transceiver-dense blades; distribute load. Thus, the conjugation of high power propagation and tight bending, resulting from the actual FTTH infrastructures, is responsible for fibre lifetime reduction, mainly caused by the local increase of the coating temperature. This effect can lead to the rupture of the fibre or to the fibre fuse. This article explains what goes wrong, why it matters, and practical steps engineers and operators can take to prevent and mitigate heat-related issues. High temperature impacts several internal parts in different ways: Laser diodes (DFB, VCSEL): Output power and wavelength shift with temperature. Additionally, Deco BE85 is equipped with a built-in fan designed to dissipate heat effectively, ensuring proper functionality of. Fiber optic cables are designed with varying temperature thresholds depending on the materials used. Standard fiber cables typically function well within a range of 85°C to 125°C. However, high-temperature resistant fibers, especially those coated with polyimide or specialized acrylates, can endure. Heavy data traffic, poor heat dissipation, high ambient temperature and component aging easily overheat optical transceiver, resulting in signal degradation, higher bit error rates, shorter transmission distance and even module failure.