I present a gauge-invariant approach for computing bubble nucleation rates at high temperature in the presence of radiative barriers. Using the Abelian Higgs model as an illustrative example, I first apply this framework using the high-temperature approximation often adopted in model-building and phenomenological studies. Subsequently I recast it in the dimensionally-reduced high temperature effective field theory, which allows one to delineate clearly the approach’s limits of validity while clarifying some confusion in earlier literature.