I have seen a few threads about not using pyrex because of explosion issues. I am not sure if there are some other reason for the explosion, but I just want to tell all my cooks out there (both rookie and veterans of the kitchen) that you cannot...ABSOLUTELY CANNOT expose a pyrex dish or any glassware to extreme temperature change, it WILL shatter and probably cause some damage. When removing pyrex or glass from the oven, you cannot run it under water (cold), better yet, don't put it in water at all nor on anything cold, it will shatter. As for glass pot covers, same issue.
To properly care for pyrex, all glasswares and glass pot covers, leave it on the stove to cool off (This is ok if the stove is still warm from prior use). Below is an image of what happened to me after I baked a bread. I didn't have any where else to place the dish right out the oven, so I placed it on the side, but piece of the dish was touching the cold metal service at the edge of the sink. I lost a good pyrex dish with such careless behavior.
I should have known better. I knew about the hot and cold issue, but the cold metal service was a live experience. Putting a hot pyrex on top of a cold metal service will cause the same effect of a broken or shattered glass (if removed from oven and into cold water). So, the affect of exposing glass to extreme temperature change will be the effect of shattered glass. Be careful...there most likely isn't anything wrong with the pyrex or glassware, most incidents happen because of misuse. I also lost a beautiful belgique pot cover because my fiancee (at the time) decided to remove my pot cover from the boiling pot and place in under cold running water...it couldn't shatter into tinier pieces O_O AY!
...Again, just set your dishes and pot covers aside until they have completely cooled off.
Happy cooking! :-D