This book continues to provide the most readable, concise, and easy-to-follow introduction to thermal physics. While maintaining the style of the original work, this new edition now covers statistical mechanics and incorporates worked examples systematically throughout the text. It also includes more problems and essential updates, such as discussions on superconductivity, magnetism, Bose-Einstein condensation, and climate change. Anyone needing to acquire an intuitive understanding of thermodynamics from first principles will find this third edition indispensable.