Enhanced transport phenomena are essential for chemical reactions in continuous-flow microstructured equipment with transitional flow regimes. The geometry and cross-section of the smallest channel determines the flow regime, pressure loss, and energy dissipation in the microchannel. Mixing and heat transfer are greatly influenced by the flow regime. Controlled reaction conditions lead to enhanced safety, especially for harsh reaction conditions at elevated temperatures or high concentrations. Safety and operational limits of these regimes are presented for optimized process intensification, with examples of nitration and organometallic reactions.