  Presuming weak collisional interactions to exchange the kinetic energy
between dark matter and baryonic matter in a galaxy cluster, we re-examine the
effectiveness of this process in several `cooling flow' galaxy clusters using
available X-ray observations and infer an upper limit on the heavy dark matter
particle (DMP)$-$proton cross section $\sigma_{\rm xp}$. With a relative
collisional velocity $V-$dependent power-law form of $\sigma_{\rm
xp}=\sigma_0(V/10^3 {\rm km s^{-1}})^a$ where $a\leq 0$, our inferred upper
limit is $\sigma_0/m_{\rm x}\lsim 2\times10^{-25} {\rm cm}^2 {\rm GeV}^{-1}$
with $m_{\rm x}$ being the DMP mass. Based on a simple stability analysis of
the thermal energy balance equation, we argue that the mechanism of
DMP$-$baryon collisional interactions is unlikely to be a stable
nongravitational heating source of intracluster medium (ICM) in inner core
regions of `cooling flow' galaxy clusters.
