Ardley, Neil.Heat. New Discovery, 1992. Defines heat and discusses its properties, origins, and uses.
Lafferty, Peter.Heat and Cold (Let's Investigate Science). Benchmark, 1995. Explains the effects of heat and cold and how these effects can be used; includes suggestions for experiments.
Olesky, Walter.Experiments with Heat (New True Books). Children's Press, 1986. Scientific explanations and experiments that demonstrate the nature of heat, for younger readers.
Challoner, Jack.Hot and Cold. Raintree Steck-Vaughn, 1996. Provides simple activities that introduce the concepts of hot and cold in relation to melting and freezing, as well as temperature measurement; for younger readers.
Morowitz, Harold J.The Thermodynamics of Pizza. Rutgers University Press, 1991, 1992. Written for the general reader, this book has chapters on many science subjects. The opening essay discusses the thermodynamics of heat transfer and heat retention using a widely available example—pizza.
Planck, Max. Trans. Morton Masius.Theory of Heat Radiation. Blakiston, Reprint, Dover, 1914. 1991. Planck's second (1914) edition. A classic text.