Why would H want to sleep on the couch (on purpose)? Does he not like the bed? Does he have back problems? Is the temperature in the bedroom not what he likes?
Before BD, whenever we would have a really bad argument, he would retreat to the couch as punishment I guess. After BD, he slept on the couch for like a month straight, then slowly made his way back to sleeping in the bed.
The temperature in the room is a problem for both of us. But we have a fan in case it gets too warm, even with the A/C on. Sometimes he'll stay up really late and according to him fall asleep on the couch, and just stay there. I normally would say something to him about it, so I'm sure that's where his statement came from.
If I'm honest, when I say something to him about sleeping on the couch, I would say I'm projecting my own fear that he's sleeping on the couch because of OW and doesn't want to sleep with me.