This chapter presents a number of real applications of urban heat island mitigation technologies. The recent research trends show that the creation of a link between the complicated results of the urban climatology and the town planners demands more design-oriented outcomes. The urban heat mitigation technologies involved measures like the increase of vegetation, the use of shading, as well as the use of materials with appropriate thermal properties. The main urban heat island mitigation technology is the water of the river and the cooling of the adjacent areas via evapotranspiration. The cool roof technology has also direct consequences on the building thermal loads, which were measured either with the indoor air temperatures or the AC energy demand evolution. The air conditioning systems are more widely used in hot climates like in Mediterranean regions as Greece, Italy and a large area of United States, concerning the reviewed case studies. The results demonstrate the potential for typical buildings with weak insulation systems.