When we heated the two slippers in the microwave as directed, they did come out warm to the touch. But they both were unpleasantly damp from the heating process. The included instructions say this occurrence is to be expected and will improve with time and regular use. I just didn't like my feet in such a warm AND damp environment. I was also surprised that this product is not designed to be walked in. So you have to keep a pair of regular slippers with you unless you want to pad around barefooted on cold floors. Not very convenient. Again, the included instructions say this product is not designed for walking. However, neither of these shortcomings were mentioned in the product description. I would not recommend purchasing these "slippers."