In many plasma-aided manufacturing systems, metallic or ceramic particles are introduced in a thermal plasma. The heat transfer from the plasma to the particle, in part, governs the quality of the products. To design thermal plasma-aided manufacturing systems and to predict their performance, accurate determination of particle heat transfer is necessary. In this paper, a spherical particle introduced in an ionized gas made up of electrons, ions, and neutrals is considered. A model to accurately determine heat transfer to the particle is developed.