This was a constant refrain of my childhood. Just in case, it's not rude, it means close the door!
In those days it was perfectly reasonable to have only one warm room (two including the kitchen) and keep doors closed to keep the heat in that room and avoid drafts. Bedrooms would be cold with plenty of blankets, thermal PJs and maybe an electric blanket.
Would it really be so awful to go back to that. Haven't we got used to being wasteful of both cash and natural resources but expecting the whole house to be toasty, even little used rooms and leaving internal doors open? Is this the end for open plan living?