Temperatures of dust (red line) and gas along the HIFI cut. The gas temperature as derived fitting low-J lines (IRAM data, blue line) is systematically lower than the derived gas temperature fitting both low and high-J lines (IRAM and HIFI data, black line). T_gas (from both low and high-J lines) is systematically higher than T_dust, at least along this cut. The errors vary between ~5−15% throughout the cut with the higher accuracy close to the central position.