Our living room has a (currently-decorative) fireplace in the middle of one wall, with L-shaped radiators on either side. (In a bit of cleverness, somebody built window-seats over those radiators.) Erik in particular likes to lie in front of these radiators, using the L shape and body curve to maximize the thermal properties of the arrangement. Even though there are two radiators he and Baldur will sometimes fight over one of them; the one on the left seems preferable for reasons known only to cats.
When Erik lies along this radiator he always orients himself in the same way, facing into the room (instead of facing the fireplace). I've gently chided him that he needs to warm the other side sometimes, but you know how cats are about listening.
But now he seems to be taking my advice: for the last few days I have noticed him not changing orientation (that would still be wrong, apparently) but alternating radiators. Ok, that works too. :-)
(I really ought to get him a thermal bed as
alienor suggested.)