An intake system for a turbocharged internal combustion engine and a method for controlling warm-up of a turbocharged internal combustion engine are provided. The intake system includes an intake manifold defining a plenum chamber connectable to a plurality of engine cylinders, an intake duct opening into the plenum chamber and supplying a gaseous fluid thereto, an electric heater provided for heating the gaseous fluid, and a cooler supplied with a cooling fluid, provided for cooling the gaseous fluid. The heater and the cooler cooperate to form a conditioning module positioned within the plenum chamber in such a way as to intercept at least a substantial part of the gaseous fluid entering the plenum chamber from the intake duct, wherein the cooler is arranged in series with the heater.