"Time dependent energy conservation in a control volume refers to a fascinating and challenging portion of heat transfer called unsteady state or transient heat transfer. Energy conservation in first law of thermodynamics states that heat inflow into a control volume, plus the heat generated in a control volume, minus heat outflow from a control volume equals to change in internal energy of a control volume. Energy conservation differential equations for transient heat transfer in cartesian, cylindrical and spherical coordinates have been determined in numerous heat transfer text books such as References 10 and 15 and also presented in the Appendix of this book. This book investigates twenty-four transient heat transfer problems in our everyday lives. I chose wide variety of simple and every-day life problems in order to give readers insight into different approaches to a solution in transient heat transfer. Sensitivities of dependent variables to governing independent variables are investigated under appropriate physical conditions"--