In my neck of the woods, they're called "the cone of shame".
An interesting thing happened tonight. My brother and his wife are in town to celebrate my mom's 89th birthday. Unfortunately, most times when they visit everything turns upside down in a way. It's the first day of their visit but things have started going south already. I invited Mom and them to dinner at my house and everything was going well until at 7:30-ish, I advised them to start heading out because "in an hour or two, it's going to start freezing and will get icy." Maybe I should have drawn them away from Mom's hearing before I said that. Everyone bundled up and started up the stairs. There are about eight steps up from my house to street level. My brother held Mom's arm and she had her cane. I went behind them but shone the flashlight on the ground in front of them. My brother's wife went ahead. At the top of the steps, she said, "Okay, this is completely iced over." We came on and there was no ice, but my mom stiffened up and had to be coaxed up the last few steps. When she got into the car, she said, "This is horrible." It completely negated the whole day for me, although I realize that just isn't fair.