The adjacent item on exploding Pyrex reminds me that I like to post this from time to time as a caveat. When I took a hot steamy pot lid off the pot and placed it on my glass cooktop, it set up such a suction that it caused the cooktop to crack diagonally from one end to another. (My scientist husband and a scientist neighbor stood scratching their heads and agreeing that they would not have thought this possible, but we had to replace the cooktop, nevertheless.) So, a warning---set the hot steamy lid down so that it protrudes over the edge of the cooktop and air can get up under it. Just saying.