In Food industries, thermal treatments are generally regarded as essential steps to influence several subsequent processes as well as the safety of the final food products. Accordingly, heat transfer mechanisms during high-temperature treatments need to be widely studied to monitor their effects on milk and dairy products, which help in reduction of pathogenic organisms, minimizing microbial growth, and improving the sensory properties of the food. This chapter illustrates the fundamentals of heat transfer and fluid-flow characteristics along with various techniques of Pasteurization adopted by Food and Dairy Processing industries. Specific heat/thermal conductivities of fluid milk and dairy products; which affect the characteristics of the food are also highlighted here. Thermization, sterilization, high-temperature short-time (HTST) pasteurization, low-temperature long-time (LTLT) pasteurization, and ultra-heat treatment (UHT) are a few conventional heat treatment techniques; whereas, emergent techniques are Infrared Radiation, Microwave Heating, Ohmic Heating, Pulsed Electric Field, and High-Pressure Technology applied in milk and dairy industries. In dairy plants, higher temperature short-time pasteurization (HTST) is preferred over other pasteurization methods because it maintains several heat-sensitive vitamins and enhances the products’ sensory attributes.