To reduce the amount of air input to a patient warming blanket, when the blanket is of a size that does not require the full amount of air output from a convective warmer for optimal pressurization, a regulator is provided to the inlet of the blanket to restrict the amount of air input to the blanket, thereby reducing the airflow rate to one that is appropriate for the optimal inflation or pressurization of the warming blanket. Respective regulators that allow different amounts of air under pressure to pass therethrough may be correspondingly fitted to blankets of different sizes and/or dimensions. Each regulator fitted to the inlet of the blanket may be configured in the form of an adapter with multiple orifices for passage of air, or a filter made of an air permeable material having a preselected porosity.