Hello99, the question is how hot does the metal get. I spoke to him Friday night, and he told me that the old bulbs had a heat element, but because that wasn’t the main part of the bulb it was a davar sh’eino miskaven, and therefore it would be assur for a Jew but you could ask a goy. He told me that today’s bulbs don’t get as hot, so he believes that it would only be a derabanan even for a Jew to turn it on. I will iy”h try doing my own research on this. It’s only bishul if it becomes red-hot like a filament. If it gets hot but doesn’t glow it’s not bishul.
I checked the dirshu M”b but nothing on the kids and holding them by light bulbs- I checked both 334 and 343.