I live in Texas - and I laid mine out with the back side down (so I guess my bubbles were on the top). I left it out all day in the sun on the concrete. More or less the bubbles were gone. I think I can still slightly tell where my mat was distorted. Have thought about laying it out one more day, maybe with a heavy book or board on it. However, as I still used this mat before (I just avoided the bubbled area) - I will still use it now - and as I mentioned - mostly the area is flatted out.