Bubble nucleation could hardly be noted in microscale boiling systems even under high heat flux, denoting as the fictitious boiling phenomenon. We investigated in this work the role of perturbations on the dynamics of clusters, whence developing the physical interpretation of the fictitious boiling commonly observed in microscale boiling. Both the effects of internal and external perturbations were examined. The external perturbations could markedly depress the development of clusters, thereby correlating with the bubble-extinction characteristic noted in fictitious boiling. A pressure fluctuation model was proposed to provide a criterion to the occurrence of fictitious boiling.