An experimental study of cooling an array of multiple heat sources simulating electronic equipment by a single row of slot air jets positioned above a critical row (row having maximum heat dissipation rate) of the array was conducted. The other low power rows of the array were cooled by the spent air flow from the air jets. The experimental work was carried out in two phases. In the first phase, each block of the array was heated at a time and the other blocks of the array were kept unheated. The Nusselt number of each heated block and the thermal wake effect on downstream blocks were investigated and correlated for different values of jet Reynolds number, position of the block with respect to the jet impingement point and the separation distance between the orifice plate and the impingement surface. A superposition technique was implemented to demonstrate the practical importance of the present correlations in predicting the operating temperature of any block in an array with multiple heated blocks. In the second phase, the experiments were carried out with heating all the blocks at the same time. This phase was carried out to verify the superposition technique used to predict the operating temperature of the blocks of the array in the case of the multiple heating. (c) 2006 Elsevier Ltd. All rights reserved.