Regulations and laws about exposure to electromagnetic fields (EMFs) require that it constantly remains below some fixed limits. It is demanded therefore that the experimenter make a decision about the conformity of measured values to such limits. The statement may indeed be reliable only up to a certain degree because of the uncertainty that affects the available measurements; thus, the possibility that the wrong decision is made because of the limited amount of knowledge available about the process must be considered. Ultimately, the task is to determine the most reliable condition of the EMF while minimizing the cost caused by a wrong decision. Based on a distributed system of mobile probes, a fuzzy logic approach to a decision-making procedure is presented in this paper and applied to the results obtained during a measurement campaign.