<p>This paper deals with oscillations in a straight fin exposed on both sides to periodic temperature variations with different amplitudes, frequencies, and phases (or phase difference). The linear governing equation of the fin was solved using complex representations. The temperature distributions along the fin were expressed as functions of the relevant parameters over time. The results show that increasing the oscillation frequency reduces heat penetration into the fin, and that very high frequency acts as a barrier to heat transfer. It was also found that the temperature within the fin does not respond instantaneously to the imposed temperature fluctuations. Most of the temperatures along the fin remain within the range defined by the smaller forcing amplitude. The effects of parameters such as the convection coefficient, thermal conductivity, material density, and specific heat capacity were presented and discussed.</p>