Heat management in electronics is a critical challenge as computer chips become more compact and powerful, leading to overheating issues in laptops, servers, and data centers. MIT researchers have developed a groundbreaking technique to study heat transfer in multilayered materials, combining X-rays and laser pulses. This method provides unprecedented insights into heat flow at the micro and nanoscale, allowing for the detection of defects as small as a single micron. The study revealed a fourfold reduction in heat transfer efficiency due to a defect, highlighting the importance of understanding heat carriers and their impact on device performance. The technique, which can be applied to various materials and devices, has the potential to revolutionize the design of electronic systems, enabling better thermal management and more efficient power-dense computers and electronics.