We apply the boson–fermion chemical equilibrium model to derive an expression for the electronic specific heat at zero field and calculate also the magnetic field dependence of the specific heat coefficient γ(T,H)=C(T,H)/T in external magnetic field H. The carrier densities for bosons (B ++ ) and fermions (h + ) are determined by the treatment of the equilibrium reaction B ++ ⇌2h + , in a magnetic field. The densities for bosons and fermions, n B (t,h) and n h (t,h) determined in terms of a single, universal function f(t,h), where the scaled variables are defined by t=T/T * and h=H/H * . For zero field we show that the electronic specific heat coefficient γ(t,0) comes out to be in semiquantitative agreement with experiment at all temperatures. The main contribution comes from localized bosons forming stripes of localized charge in addition to the fermion contribution. The model predicts the specific heat step at T c to come from localized bosons with spin unity, which are 3D-paramagnetic below T c and 2D-antiferromagnetic above T c . Because the boson density increases with doping we predict the peak value to be larger for overdoped compounds. The main test for the theory is the derivation of the scaling function at low temperatures γ(T,H)/H 1/2 ∼(1+(z/z 0 ) 2 ) 1/2 , with z=T/H 1/2 .