Originally Posted by Nan'sMom
Not to be a buzz kill here but google "exploding Pyrex" and you can check it on Snopes. A bit frightening.
The "exploding pyrex" reports were generally associated with extreme and sudden temperature changes. I wouldn't worry about using it in a slow cooker because they do not get extremely hot and they do change temperatures very gradually. An oven is likely to get hotter and experience more rapid temperature changes than a slow cooker and most pyrex is rated as oven-safe.