This paper investigates the applicability of organic and inorganic thermal parameters in a range of thermal conditions, from diagenesis to epizone, and in HP–LT settings within the framework of continental subduction and exhumation in the southern Apennines, where independent thermobarometric constraints are available. Two juxtaposed tectonic units, the HP–LT Lungro–Verbicaro Unit (in the hanging wall) and the non-metamorphic Pollino–Ciagola Unit (in the footwall) have been analysed. For the Lungro–Verbicaro Unit, clay mineral thermal parameters and vitrinite reflectance underestimate metamorphic conditions (constrained by petrology), suggesting that, in relatively HP units, these indicators are ‘retarded' and strongly depend on