The dynamics of five dimensional Wilson line phases at finite temperature is studied in the oneloop approximation. We show that at temperatures of order T ∼ 1/L, where L is the length of
the compact space, the gauge symmetry is always restored and the electroweak phase transition
appears to be of first order.
We focus on a specific model where the Wilson line phase is identified with the Higgs field
(gauge-Higgs unification). The transition is of first order even for values of the Higgs mass above
the current experimental limit. If large localized gauge kinetic terms are present, the transition
might be strong enough to give baryogenesis at the electroweak transition
