Recently we developed a numerical technique to compute chiral symmetry breaking at T = 0 with different current quark masses m0, including the current quark masses of the six standard flavours u, d, s, c, b, t. We also fitted from Lattice QCD data the quark-antiquark string tension σ dependence on temperature T . We now utilize σ(T ) to further upgrade the chiral invariant and confinement quark model to finite temperatures T = 0. We study the quark mass at finite T and obtain the corresponding chiral crossover at T = Tc. The quark mass critical curve has a shape similar, but not identical, to the string tension critical curve. In the case of the lightest quarks, the quark mass and the chiral condensate essentially vanish at T = Tc, except for the small explicit chiral symmetry breaking mu and m d .