My neighbor made one herself............just take a human heating pad, and place it between 2 towels or under a favorite bed, etc. Make sure when you plug it in, there is no hazzard to you or your kitties (pulling the plug out, or if you have a wire biter ) place the setting on low, and place kitty in new warm and fuzzy bed!

My neighbor actually has hers outside in the kitty house, and she turns the heat on every night for them...........they just love it!!