I did the same thing and mine was new made me sick

I wish I could say that I have never done that. I accidentally ironed mine as well. I will try some of the suggestions here. Thanks for asking the "smart" question so I could learn as well.

what a great idea---i never thought of that.

I did the same thing and ended up buying a new one. Recently someone posted that she put it in the oven on low heat and used a flat surface and heavy books to weigh it down for cooling. According to that member, the mat went flat again. You may want to do a search on cutting mats.

I gave a really large mat to my Mom a few years ago when she showed an interest in quilting, but she only made one quilt before losing the passion. She recently gave it back to me, but had stored it under her bed with half of it on top of a small box so it warped. Thanks for the hot-car-in-the-sun idea, I will try that!

Here I thought I was the only one who did that!! What was I thinking to iron on it even with a towel?? Live and learn.

It happened to me too!! I had read that you warm up your oven, then turn it off and place mat in oven with something heavy on it. Within half an hour my mat was perfect again!

Throw away. Not only will it not warp back to shape, there will also be awful smell coming from it. WE ALL learned the hard way. So sorry you did too.

Put in back in the car for an hour or so on a sunny day and when it's warm, put it between your mattress and box springs for a day or two! I've done this and it works!

I bought a large one in summer about 4 years ago, put into daughter's car with shopping on top and completely ruined by the time we got back to her house. I tried most things to flatten it again but the bumps remained; now I've followed Alex Anderson's advice and cut it up into smaller mats, discarding the bubbly parts, after buying a new larger one of course!!!