Double heat exchanger radiator assembly

The disclosure generally relates to a heat exchanger apparatus having first and second heat exchangers arranged in a parallel configuration to receive a first fluid (e.g., a hot fluid) to be subjected to a heat exchange operation (e.g., cooling of the hot fluid). The first and second heat exchangers are further configured in a series configuration with respect to the flow of a second fluid to be used as a heat exchange medium (e.g., a cold fluid to be heated by the first, hot fluid). The heat exchanger apparatus can be used as a radiator (e.g., engine coolant heat exchanger) for a motorized vehicle, in particular a heavy vehicle intended for use in relatively hot ambient environments (e.g., an armored fighting vehicle adapted for desert use at ambient temperatures above about 100° F.). The disclosure also relates to methods of using the heat exchanger apparatus, for example in the motorized vehicle setting.