“…The recently proposed method of critical fluctuations (MCF) has specifically been developed for the analysis of time series sourced from thermal systems governed by nonlinear intermittent dynamics (Contoyiannis & Diakonos, ; Contoyiannis et al, ). MCF is capable of identifying the existence of critical state, implying second‐order phase transition in equilibrium, as well as the departure from it, while it has successfully been applied to a wide variety of dynamical systems ranging from theoretical thermal systems to geophysical, biological, electronic, and financial ones (Contoyiannis et al, ; Contoyiannis, Diakonos, Kapiris, et al, ; Contoyiannis, Diakonos, Papaefthimiou, & Theophilidis, ; Contoyiannis et al, , ; Ozun et al, ; Potirakis et al, , , , ). In the following we provide a brief presentation of the key theoretical aspects of MCF as well as a step‐by‐step procedure for its application to a time series.…”