A cooling system (10) for transferring heat from a heat load to an environment has a volatile working fluid. The cooling system includes first (12) and second (14) cooling cycles that are thermally connected to the first cooling cycle. The first cooling cycle is not a vapor compression cycle and includes a pump (20), an air-to-fluid heat exchanger (30), and a fluid-to-fluid heat exchanger (40). The second cooling cycle can include a chilled water system for transferring heat from the fluid-to-fluid heat exchanger to the environment. Alternatively, the second cooling cycle can include a vapor compression system for transferring heat from the fluid-to-fluid heat exchanger to the environment.
