Marlo zinc will melt if it becomes very hot. Marlo is best stored under 25 degrees celsius and will melt at temperatures over 75 degrees celsius. We understand that many surfers will leave Marlo in the car where it could potentially melt. If your Marlo does get too hot and melts – put it in a cool place until it resets. It should be fine to use once reset but we recommend that you do not allow this to happen repeatedly.