In this paper mathematical models are formulated in order to simulate heat production and corresponding temperature changes which accompany the propagation of an axon potential. Based on earlier experimental results, several models are proposed. Together with the earlier system of coupled differential equations derived by the authors for describing the electrical and mechanical components of signalling in nerve fibres, the novel results permit to cast the whole process of signalling into one system. The emphasis is on the mathematical description of coupling forces. The numerical results are qualitatively similar to experiments.