A flow distributor assembly (13) for distributing a fluid flow across at least two surfaces (15) to be cooled is disclosed. The flow distributor assembly (13) comprises a first flow distributor (1a) and a second flow distributor (1b). Each flow distributor (1a, 1b) has a set of flow cells (3) formed therein, and comprises a connecting region. The first connecting region and the second connecting region are adapted to interconnect in such a manner that the first flow distributor (1a) and the second flow distributor (1b) are joined to form the flow distributor assembly (13), and in such a manner that the first connecting region and the second connecting region in combination define an inlet manifold (9) and an outlet manifold (10), the inlet manifold (9) and the outlet manifold (10) being fluidly connected to each of the flow cells (3) of the first set of flow cells (3) and the second set of flow cells (3). Also disclosed is a cooling unit (17) comprising a housing (14) and a flow distributor assembly (13) arranged in an interior part of the housing (14). The two flow distributors (1a, 1b) allows fluid flow to be distributed across at least two surfaces (15) to be cooled. The flow distributor assembly (13) is easy and cost effective to manufacture because the manifolds (9, 10) are automatically formed when assembling the flow distributor assembly (13).