In order to calculate the α-decay half-lives of a wide range of heavy and superheavy nuclei, we introduced a modified temperature-dependent surface energy coefficient in the proximity potential based on thermal properties of liquids and hot nuclei. An increase in the α-decay half-life was observed by decreasing the surface energy coefficient as a result of temperature incorporation of the parent nuclei. The introduced temperature-dependent surface energy coefficient evaluated the half-lives which were in good agreement with the experimental data. Moreover, the results of the present paper confirm the closed-shell effects.