A plurality of channels are formed in a base, e.g., a substrate of an integrated circuit, each channel extending between edges of the base. Two pairs of manifolds are provided, the first pair communicating with a first group of channels and the second pair communicating with a second group of channels, the first group of channels and the first pair of plena isolated from the second group of channels and the second pair of plena. Each of the pairs of manifolds includes multiple branches coupled to the channels and a common plenum. Cooling fluid is injected into the channels from different sides of the base, causing fluid to flow in different directions in the two groups of channels, the channels in thermal contact with the integrated circuit.