Why are millisecond pulsars (MSPs) hotter than expected? This research explores the heating mechanisms of these old neutron stars, challenging conventional cooling scenarios. While standard models predict low surface temperatures, observations reveal significantly higher values, prompting a search for alternative heating sources. The study investigates Joule heating in the crust, focusing on small-scale magnetic field structures. By assigning upper limits to the strength of single-field components, the authors propose that the decay of these small-scale components may contribute to the elevated surface temperatures of isolated MSPs. These findings offer a potential explanation for the thermal properties of MSPs, enhancing our understanding of neutron star evolution and magnetic field dynamics. This research paves the way for further investigations into the complex interplay between magnetic fields and thermal behavior in these fascinating celestial objects.