this depends on a number of factors, with the ambient temperature playing a particularly important part. As semi-conductors, LEDs have many temperature-dependent parameters such as forward voltage, wave length [...] efficacy. Accordingly, at high ambient temperatures (> 60 degrees Celsius), the LED suffers and there is a greatly reduced lifespan. The rule of thumb here is that a temperature exceeding the permissible maximum [...] maximum by 10 K halves the service life. However, sub-zero temperatures, such as -50°C which can be experienced in the Arctic, also bring LEDs up against their limits as the lights are subjected to high mechanical