A coolant conditioning system is provided for supplying a coolant flow to a fuel processing subsystem. The coolant conditioning system includes a coolant preheater to transfer heat from a reformate flow to the coolant flow, a heater to selectively add heat to the coolant flow in response to the coolant flow dropping below a minimum temperature, at least one outlet flow path to provide a portion of the coolant flow to at least one fuel processing subsystem, and a return flow path to return a remainder of the coolant flow to a storage tank. The coolant conditioning system is dynamically controllable to provide a portion of the coolant flow above a minimum temperature to reduce or prevent condensation of the reformate flow in selected components of the fuel processing subsystem that receive the portion of the coolant flow.