  The temperature correction to the free energy of the gravitational field is
considered which does not depend on the Planck energy physics. The leading
correction may be interpreted in terms of the temperature dependent effective
gravitational constant G_{eff}. The temperature correction to G_{eff}^{-1}
appears to be valid for all temperatures T<< E_{Planck}. It is universal since
it is determined only by the number of fermionic and bosonic fields with masses
m<< T, does not contain the Planck energy scale E_{Planck} which determines the
gravitational constant at T=0, and does not depend on whether or not the
gravitational field obeys the Einstein equations. That is why this universal
modification of the free energy for gravitational field can be used to study
thermodynamics of quantum systems in condensed matter (such as quantum liquids
superfluid 3He and 4He), where the effective gravity emerging for fermionic
and/or bosonic quasiparticles in the low-energy corner is quite different from
the Einstein gravity.
