Midplane radial (bottom) and vertical temperatures (top) at 1, 5, and 25 AU for an embedded 0.1 M_⊙ disk and an accretion rate of 10^-5M_⊙ yr^-1 irradiated by L_⋆ = 1 L_⊙. The red dashed (bottom) and solid (top) lines indicate the thermal structure of a passively irradiated disk (T_irr) calculated by the Monte Carlo simulation. The blue solid lines indicate the temperatures including the viscous heating (). The viscous temperature as calculated from Eq. (6) is indicated by the dotted blue lines.