A medical wound covering for controlling blood flow includes a flexible sheet for covering or surrounding the anatomical site of a wound, such as a surgical drape. The flexible sheet includes a plurality of electrodes electrically connectible to a stimulation power supply. Upon receipt of power from the stimulation power supply, the electrodes supply electrical impulses to the anatomical site of the wound in order to stem or arrest undesired bleeding. In some cases, the stimulation power supply is an interferential therapy power supply, and a pair of electrodes supplies electrical impulses at two different frequencies, the electrical impulses provided at two different frequencies giving rise to at least one beat impulse having an interference frequency. The beat impulse activates the sympathetic nerves to induce vasoconstriction in the local blood vessels. Alternatively, the beat impulse can be programmed to target the parasympathetic nerves if vasodilatation is desired.
