Variation of the characteristic thermal misbalance damping timescale 𝒯_M with magnetic field, and with different power-law index c where ℋ ∝ ρ^1/2T^−7/2B^c. Scanning down the column shows how the damping time changes as magnetic field B₀ decreases: panels (a) and (b) at 100 G; panels (c), (d) at 12 G; panels (e), (f) at 4 G. Comparing left-to-right shows the effect of a different power-law index c (left side c = 0, right side c = 1), whilst all other parameters are held the same. Symbols correspond to specific plasma conditions (see Table 1). We note that panels (a) and (b) are practically identical, since the plasma-β everywhere in these plots is sufficiently close to zero for the infinite magnetic field approximation to apply, which is independent of ∂Q/∂B (see Sect. 3.2).