My MIL watches my LO two days a week while I work. Tonight she told me that she was boiling my babys bottles and accidentally melted a few of them. She said they are melted from the outside and are still okay to use. My question is: if the plastic has melted on the outside a little, ARE they safe to use? Or will chemicals release? Am I even making sense lol? I will just buy some new ones if this could be harmful to my child...I use avent Phillips bottle. please reply