I have several heated pet bed type things. I have:
(they seem to work okay, but it is self-reflecting, so it doesn't get really warm OTOH, they don't need electricity, so it's great for the car)
had these for years. warm heat, not too hot even w/o the temp control. i have one i think i'm going to have to retire, cut the dogs seem to like them
work great if the dog will sleep on it, it will stay warm all night. great for the car/shows as it doesn't need electricity, but it won't stay warm for more than a few hours if the dog isn't on top of it
boyz got these for xmas last year. i made a little slip cover for them and put it on a time for each boy. nice and warm. Jet's is in his bed and Diggie's is where he naps in the afternoon.
looks very promising, but not something i have (yet)
i did not get all of these items from jeffers, but i knew they carried them all. Mostly my older kids just nap on the sofa, chair, etc., but i do have a large foam dog pad. I'd bought an ortho bed for the old lab and when the foam wore out, i just replaced it with the thickest foam I could find at Joann's.