 It melts and looks like a house fire was right next door and it turned into string cheese. So you can have some serious problems with the heat coming off a hot summer day. That can be the first problem. Second of all, vinyl, as we know, expands and contracts a lot. So if you're out there on a cool day and you're doing a drastic color change, that is going to be okay. Let's say it's 70 degrees, you're out painting it.