Radiation management (RM) has been proposed as a conceivable climate engineering (CE) intervention to mitigate global warming. In this study, we use a coupled climate model (MPI-ESM) with a very idealized setup to investigate the efficacy and risks of CE at a local scale in space and time (regional radiation management, RRM) assuming that cloud modification is technically possible. RM is implemented in the climate model by the brightening of low-level clouds (solar radiation management, SRM) and thinning of cirrus (terrestrial radiation management, TRM). The region chosen is North America, and we simulate a period of 30 years. The implemented sustained RM resulted in a net local radiative forcing of -9.8 Wm and a local cooling of -0.8 K. Surface temperature (SAT) extremes (90 and 10 percentile) show negative anomalies in the target region. However, substantial climate impacts are also simulated outside the target area, with warming in the Arctic and pronounced precipitation change in the eastern Pacific. As a variant of RRM, a targeted intervention to suppress heat waves (HW) is investigated in further simulations by implementing intermittent cloud modification locally, prior to the simulated HW situations. The intermittent RRM results in most cases in a successful reduction of temperatures locally, with substantially smaller impacts outside the target area, compared to the sustained RRM.