Thermal Monopoles

Evidence is given that some particles with large charges in gauge theories, including 4d N=4 SU(3) and 5d theories with N=1 supersymmetry, have macroscopic entropy. The ground state entropy is found to be extensive in the charges. The mass gap for excitation is estimated and is of the same order as the binding energy. The question of the decay of excited states through Hawking radiation is raised. The analysis is based on the model of (p,q) string webs and on various other results. The evidence points to an explanation in terms of a string model.