Certain types of equipment cannot be installed or operated in standardized test sites because of size, power, or safety constraints. As the typical EMC standard test procedures are hardly applicable in such conditions, the in situ evaluation emerges as the most practical alternative. Some meaningful examples where in situ EMC testing is required are PV systems, large robots, and some elements of the EV charging infrastructure. This lecture dives into the topic of in-situ electromagnetic emissions test methods and discusses why they are so important yet controversial. For this purpose, the difficulties faced when performing interference assessments under uncontrolled on-site conditions are analyzed and broken down. Then, the state of the art concerning in-situ emissions measurements is summarized to identify the gaps in the established methodologies. The latest research results will be overviewed, emphasizing the outcomes from European-funded research projects. As part of such projects, significant progress has been made in aspects such as faster instrumentation, multi-channel measurements, and ambient noise mitigation based on time-domain techniques. Moreover, recent standardization initiatives will be discussed, highlighting the aspects where industry and regulation authorities struggle to find consensus and technical compromise.