During the “current spike”, high current is flowing through the lowest impedance parts of the capacitor and as this a “high frequency” ripple load type, the current path will flow first mainly through a “surface skin effect“ area of conductive materials. The capacitor dielectric may be then subjected to immediate high electrostatic mechanical pressure force once the electric field on electrodes is created. Depending on duration of the surge spike, Joule heat is generated that has to be absorbed by the capacitor. This is indeed more relevant to the dI/dt transient discussed in the next chapter, but the initial spike may generate some “pre-conditioning” stage of the capacitor and a total energy to be dissipated by the capacitor during the power on sequence has to be considered.