This study employed a thermal/spectral technique for examining self-heating effects in high-power light emitting diodes (LEDs). Here, high-power LEDs were thermally stressed, and the impact of self-heating effects was characterized in terms of luminal performance. Results from high-speed thermography demonstrated that these thermal effects lead to degraded device performance, reduced power conversion efficiency, and power loss. The ability to monitor and quantify thermal transients using this approach is important for many optoelectronic and lighting applications. Temporal thermal and spectral characteristics were examined with the purpose of improving thermal management strategies. (C) 2010 Elsevier Ltd. All rights reserved.