  The recently discovered sharp peak in the K+/pi+ ratio in relativistic
heavy-ion collisions is discussed in the framework of the thermal model. In
this model a rapid change is expected as the hadronic gas undergoes a
transition from a baryon-dominated to a meson-dominated gas. The transition
occurs at a temperature T = 140 MeV and baryon chemical potential muB = 410 MeV
corresponding to an incident energy of 8.2 GeV.
