In some examples, a system is disclosed that includes a roller assembly for a printer. The roller assembly includes a pressure roller, a belt coupled, a drive assembly to rotate the pressure roller and to urge the pressure roller into the belt, a heater to apply heat to the belt, and a temperature sensor to detect a temperature of the belt. In addition, the roller assembly includes a controller to increase a pressure applied to the pressure roller from a first to a second pressure in pressure in response to a temperature of the belt being greater than or equal to a first temperature threshold. Also, the controller is to initiate an advance of a print media to contact the belt in response to the temperature of the belt being greater than or equal to a second, higher temperature threshold.