I have been sending glass bottles to daycare where they use a bottle warmer to warm up DS's bottles. Yesterday, one broke all around the bottom of the cylindrical part (so the entire bottom came off as one piece and all the BM in it was lost

( ). I don't use a bottle warmer at home so have no experience with them. I'm not sure if it was the bottle warmer or a defect in the glass that would have caused the bottle to eventually break. Has any one had experience with glass bottles in bottle warmers? Are you not supposed to use them with glass? Has anyone had a glass bottle break?
Re: Glass bottles and bottle warmer...
Married DH 7/30/11
CSC arrived 5/7/12
CHC arrived 6/2/14
IF, 5 losses, 1 son, 1 on the way.
My daycare won't take glass (in part because of this) so I use plastic when he goes to daycare (they just give it to him cold and I hand wash them in tepid water at home).