A novel procedure utilizing an inverse thermal modelling approach is designed to calculate palaeo-climate attributes responsible for the initiation of periglacial features indicative of the base of the palaeo-active layer. We demonstrate its performance on the example of relict sorted nets in the Krkonoše Mts., Czech Republic, and provide unique palaeotemperature and palaeo-permafrost estimates for the Late Glacial or Early Holocene.