I have been a customer of yours for about a year and have used footwarmups a lot. I alwayse have cold feet so I use them year around and was satisfied until last week. Iput a foot warmup in each shoe last Sunday morning about 1P.M. my right foot started to hurt. I took off my shoe and found that I had a water blister the size of a half dollar on the sole of my foot. The foot warmer was really hot. Now a week later I have a very sore foot and the Doctor said it will be slow healing. The warmer in the left shoe was okay (not too hot) so it is evident something was wrong with the warmer in my right shoe. I won't be using them anymore, I will just have to endure cold feet. You have lost a regular customer.