Linked from
The 14 pages that link to Thermal management, each with the reason it gives.
Fiber laserRelated: The fiber's large surface-area-to-volume ratio aids heat removal.
White LEDRelated: Junction temperature affects LED output, efficiency, color, and service life.
Light fixtureRelated: Heat removal helps preserve LED performance and component life.
V/STOLRelated: Downward exhaust can damage surfaces and expose nearby personnel to intense heat.