Systems and methods for a temperature control loop in a vehicular engine compartment to concurrently cool at least two devices with a single fluid supply source when each device requires the cooling supply fluid to have a distinct temperature. The supply fluid, having a first temperature, can be simultaneously routed through a primary heat exchanger and a mixing valve. The primary heat exchanger cools the first temperature fluid to produce a second temperature fluid. The mixing valve controllably receives at least some of the first temperature fluid and some of the second temperature fluid discharged from the primary heat exchanger and mixes the respective fluids to produce a third temperature fluid. The second temperature fluid not diverted to the mixing valve is used to cool a first device located downstream of the primary heat exchanger. The third temperature fluid is used to cool a second device located downstream of the mixing valve.