Methods, apparatus, and products for detecting an increase in thermal resistance of a heat sink in a computer system, the heat sink dissipating heat for a component of the computer system, the computer system including a fan controlling airflow across the heat sink, the computer system also including a temperature monitoring device, including: measuring, by a monitoring module through use of the temperature monitoring device during operation of the computer system, thermal resistance of the heat sink; determining whether the measured thermal resistance of the heat sink is greater than a threshold thermal resistance, the threshold thermal resistance stored in a thermal profile in non-volatile memory, and if the measured thermal resistance of the heat sink is greater than the threshold thermal resistance, notifying a system administrator.