Data characterizing a read/write head of a hard disk drive is produced in a burn-in process. The method includes measuring the flying height of the head at a first temperature in a burn-in chamber, measuring the flying height of the head at a second temperature in the burn-in chamber, postulating a linear relationship between the flying height and the temperature of ambient air using values of the flying height measured at the first and second temperatures, and estimating the flying height of the head at a third temperature using the linear relationship. The elevation of the read/write head is then controlled based on data representing the values of the flying height as measured at the first and second temperatures and as estimated for the temperature. In particular, the amount of electric power supplied to an FOD heater of the head is controlled based on the data generated during the burn-in process.