The present volume in the series of "Experimental and Applied Heat Transfer Guide Books" is concerned with studies of turbulent heat transfer performed over a number of years at the Institute of Problems of Energetics of the Academy of Sciences of the Lithuanian SSR. It presents original experimental results on heat transfer with detailed measurements of fluid dynamics in the boundary layers of air, oil, water and glycerine flows, including the effects of variable fluid physical properties, turbulent Prandtl number and features of heat transfer in sublayer at different Pr.