Garlatti et al. 1 report theoretical simulations aimed at showing that the best molecular nanomagnets (MNMs) for magnetic refrigeration between T’10K and sub-Kelvin region are those made of strongly ferromagnetically coupled magnetic ions. The authors make impeccable calculations leading to results that, apparently, contrast with the established belief in this research field. 2 We point out that the performance of any magnetic refrigerant is largely dependent on extrinsic parameters, viz., the experimental conditions that encompass the type of thermodynamic cycle employed for the refrigeration. The main conclusion of the title work is based on assuming that the refrigeration proceeds from 10 K down to 1 mK via a single stage, governed by the Carnot cycle. This Comment revises the results in Ref. 1, while showing that the experimental conditions considered are impracticable and inconvenient. By adiabatically …