Editors’ choice for the thematic issue “Fundamental Problems and Trends in Magnetism” is the paper entitled “Materials Based on RCo2 and RMnSi for Solid-State Magnetic Cooling” by I. S. Tereshina, I. A. Ovchenkova, G. A. Politova, and N. Yu. Pankratova (Bulletin of the Russian Academy of Sciences: Physics, 2023, Volume 87, Issue 3, P. 304-309).