Article: Don't Let Thermal Runaway Run Away With Your LED Vision System

Tricky little light sources! LEDs are simple, but careful power management is needed to preserve light output and avoid the deadly combination of high current and high temperature that will cause irreversible deterioration of this expensive light source.

Fluorescent lamps and LEDs share the phenomenon called "thermal runaway", which means that increasing temperature causes less efficacy, or less efficiency, which means that proportionally less light is generated as more power is applied. In the extreme case, light output may actually decline. This is thermal runaway. LEDs are different from fluorescent lamps in that LEDs may suffer permanent damage if thermal runaway occurs unchecked.