Range hood

[crimp56]

I have a 1989 mobile home which Ive owned for six years. The range hood over my ELECTRIC stove is vented to the outside thru a wall. The damper on the vent outdoors is broken and allowing very cold air to enter the home. Its much too cold here in New England right now to replace the vent (also I'm an elderly women living alone) , but as a quick fix can I block off the vent outdoors. If so how can I block it off (with what) Also do I even NEED an outdoor vent for an electric stove? Please help.