Dust grain temperatures for a number of different sizes and dust compositions of cores embedded in spherical (black lines) or cylindrical (grey lines) filaments. The iron temperature is divided by a factor of 2. The effective values for a single temperature model of the dust grains is shown for comparison (solid curves) where the dust emissivity is approximated by a simple power law (Eq. (12)). The external pressure p_ext/k outside the filaments is assumed to be either 2  ×  10⁴ (top) or 10⁶   K/cm³ (bottom). The extinction through the filaments’ center is either 8 mag (left-hand figure) or 64 mag (right-hand figure).