  A Monte Carlo simulation study of the critical and off-critical behavior of
the Baxter-Wu model, which belongs to the universality class of the 4-state
Potts model, was performed. We estimate the critical temperature window using
known analytical results for the specific heat and magnetization. This helps us
to extract reliable values of universal combinations of critical amplitudes
with reasonable accuracy. Comparisons with approximate analytical predictions
and other numerical results are discussed.
