Roller bearings are used in mechanical setups to reduce rubbing. In some applications, the thermal dissipation involved mostly due to friction between rollers and rings is important. Correct operation of the roller is possible only if local thermal phenomena are controlled. In this work, the resulting dynamical and ther- mal fields within the enclosures limited by rollers and rings in cylindrical bearings are obtained through numerical modelling. Convective heat transfer is quantified by Nu-Re-Pr correlations for various dynamical and thermal configurations of the bearing. Two specific shape factors of the cavity and common fluids of engineer- ing interest are considered, including air, water and a specific oil. The proposed correlations complement those existing in the specialized literature concerning the cylindrical roller bearings. They are proposed for a wide range of Re including large values and can be applied in many engineering fields.