The use of Finite Elements for the modelling of heat transfer problems is here described for the first time. Applicable in Mechanical, Civil as well as in Materials engineering, it copes with heat transfer in virtually any medium including polymers and ceramics. The essential theory is covered and full implementational details given including two FORTRAN programs. HEAT2D, a program capable of steady and transient, linear and nonlinear analyses of diffusive and convective heat transfer and its adaptive version HADAPT are also presented with full instructions and documented examples. The complete source code for both programs and sample input data files are provided on a floppy disc included with the book. The programs can be run on any computer with a FORTRAN 77 compiler.