  We investigate the effects of inhomogeneous scalar field configurations on
effective action at finite temperature. Recently, Walliser et al. have
calculated the leading perturbative corrections to the wave function correction
term $Z(\phi,T)$, for the standard model at finite temperature. Here we follow
their results and apply them to calculate the effective energy of the sphaleron
solution, including derivative correction term $Z(\phi,T)$. The dominant
contribution to $Z(\phi,T)$ comes from vector boson loops. We also study the
possible effects of corrected sphaleron energy on the baryon number violation
rate in the standard model.
