This was purchased for a feral cat that kept coming to my porch. She delivered her babies soon after. I was able to get them all to the vet for preventives & shots, the momma was spayed after nursing them for 8 weeks.  The mom refuses to come.inside but she is now our outdoor cat. She loves our yard and home. She LOVES this extreme weather pad , as it's been a life saver in good old Indiana winters.    I have placed on the bottom floor of her cat house, plugged into my outdoor outlet, that's on my covered porch, constantly.   I do turn it off during the heat of the summer.   Buy 2 covers. So you can have one in rotation for washing.