  The Phi-measure of event-by-event fluctuations in high-energy heavy-ion
collisions corresponds to the second moment of the fluctuating quantity
distribution of interest. It is shown that the measure based on the third
moment preserves the properties of Phi but those related to the higher moments
do not. In particular, only the second and third moment measures are intensive
as thermodynamic quantities. The Phi_2- and Phi_3-measure of p_T-fluctuations
are computed for the hadron gas in equilibrium and the results are analyzed in
context of the experimental data.
