The cat found the heating mat for my office chair. I use this because the room is hardly isolated and it makes no sense to bring the whole room to office temperatures in the freezing winter months.
The mat has 3 different heat settings and is designed for car use, obviously. The important part is the pressure sensor so it stops heating when nobody is sitting on it.
The cat weights enough to trigger that and enjoys it as comfortable spot to nap on now 😜