I bought 6 of these mats and made my own custom 6 unit cat condo for my outside/barn cat friends. The cats loved them!!!! They spent the winter toasty warm. It was nice to see them all snuggled in- six little heads looking at me from the condo every morning when I did my barn chores. The mats all held up fine through a pretty harsh winter. And a bonus- they are environmentally friendly- they draw very little power.