@Kendall Raine Thermulation and yes it was a short in the heating element. It burned a whole right through the vest and my rashguard. I have also seen people get minor burns that last a day or two from having it on for the tender ride back to the boat. It appears in the pattern of the heating element so make sure you turn it off when out of the water. Thermulation replaced the vest when it happened but I don't think they are in business anymore.