This I've gathered from the consistency with which the amazon listings come with 1-star 'burnt my house down' reviews with pictures, and more importantly that one of the largest vendors, Sunbeam, _still_ sells blankets they know to be defective, _and_ never recalled an older model they know to be even more defective[1]!
That they are still selling them implies a regulatory failure as far as I am concerned. And if they can get away with it, so can everyone else, so no blanket for me.
Which is a real shame because holy wow, electric blankets are so much more efficient than space heaters.
In conclusion, someone please do a disrupt and sell me a blanket
[1] http://www.safetyresearch.net/blog/articles/jury-finds-sunbeam%E2%80%99s-improved-electric-blanket-circuit-still-doesn%E2%80%99t-fail-safe?fbclid=IwAR0Ayoa1n7oz-xW78CZBRwYshnlLBr2Huu0uPEk0E7YhVmTnXvtAAlvatcw