Is it such a bleak piece to cover exposure to air grilles surrounded by the winter? There is a ventilation grille within the room of every room of...

There is a ventilation grille within the room of every room of my flat, about 1 foot square. Nice contained by summer, but the cold draught coming in immediately is appalling.
Good ways to grill only just one room...
Answers:    Never cover ventilation grills. They are near for a reason. Have you hear of carbon monoxide? This poisonous, odourless gas kill....I have loosely tape a picture over mine in one bedroom as in attendance is a gale howling through. There is still enough room for the heavens to circulate. I always hold all my doors instigate throughout the year. I am an outdoorsy person so probably you wouldn't like the fear of the cooler air as I do.