  The so-called $\Phi$ parameter, which measures the transverse momentum or
energy correlations (fluctuations) in high-energy collisions independently of
the particle multiplicity, is computed for the equilibrium ideal gas. As
expected $\Phi$ vanishes for the particles obeying Boltzmann statistics but is
finite for the quantum particles, positive for bosons and negative for
fermions. $\Phi_{p_{\perp}}$, which is found for the pions gas, significantly
exceeds the value of $\Phi_{p_{\perp}}$ measured by the NA49 experiment. The
discrepancy is discussed.
