The concern about thermal performance of microelectronics is on the increase due to recent over-heating induced failures which have led to product recalls. Removal of excess heat from microelectronic systems with the use of heat sinks could improve thermal efficiency of the system. Challenges posed for the modeling of thermal phenomena in microelectronics from optimizing IC packaging thermal performance, assembly processes and reliability testing to predicting operational temperature in application environments. Precise thermal analysis is essential for designing an effective thermal management system of modern electronic devices such as batteries, LEDs, microelectronics, ICs, circuit boards, semiconductors and heat spreaders. The need for smaller, faster and lighter products has put considerable demands on the thermal management of microelectronics. This paper outlines the issues in thermal management of consumer and aerospace electronics. Some typical solutions for complex high-end systems are presented. The role of the thermal interface material is a key to the thermal management of high performance consumer electronics.