That’s the problem that occurs quite often for people who prefer to sleep on the floor. Most of the apartments and old houses do not have underfloor heating, and people get cold when they sleep on the floor. I have some problems with my neck, and I can sleep only on the floor. Even the firm mattress is uncomfortable for me. When we bought a new house, I decided that I will make a floor-bed in my room, so I can sleep comfortably. We made a low profile access floor, and raised the floor instead of my bed. We also added underfloor heating, to avoid any health problems in the future. For my “bed” I added some hidden sockets to charge my phone or laptop, thankfully it was an easy thing to do https://www.netfloorusa.com/netfloor-usa-eco-access-floor