Influence of heat conduction on quasi-discontinuous solar wind solutions. Upper panel shows heating function Q_H, T (black, Eq. (3)); heat conduction source term Q_con (red, Eq. (14)) for an exemplary slow solar wind solution (ϵ = 1 R_⊙) is shown in the range from 1 R_⊙ to 1 AU. Bottom panel shows ratio of absolute powers ϕ as a function of the heating function width ϵ for the slow (black) and fast (red) solar wind solutions.