In one aspect, a process for controlling a temperature of fluid entering a post treat reactor in a naphtha hydrotreater includes measuring a temperature of hydrotreater reactor effluent and determining a set point based on the measured temperature. The set point is transmitted to a first temperature indicator controller, and the first temperature indicator controller measures a temperature of fluid flowing into a post treat reactor and adjusts a combined feed flow through a bypass of an upstream combined feed exchanger. This reduces an amount of heat exchanged in the combined feed exchanger and thus prevents the fluid temperature of the fluid entering the post treat reactor from falling below the set point.