The possibility of measuring the heat content of the ladle lining, by a non-contact method, was studied. Plant trials were carried out at a Swedish steel plant, where the heat content of the ladle lining was determined by measuring the lining time--temperature relation with a radiation thermometer. The results showed that it is possible to determine the lining heat content quite accurately. By using the measured heat content as the input in a simulation model, the steel temperature lapse was calculated. The difference between the calculated and the actual measured steel temperature was acceptable, with a standard deviation of plus/minus 3.5 deg C. This shows that a non-contact temperature measurement in connection with a calculation model can be used to accurately predict the steel temperature lapse in the ladle