USB-heated peripherals

[DisMyMac]

Amazon sells a variety of USB-powered hand and foot warmers (mittens and slippers). They look unsafe and gimmicky, but I'm not a good judge of these things.... Has anyone tried them?

Also, why don't they sell mug warmers? Lots of people drink warm beverages while at their computer. This is supposed to be "the future" but everything still kind of sucks.

 

[PerformaGuy]

I'd be worried about a poorly designed circuit board in one of those things that draw too much power and damage the USB port.

I know Mac USB ports are supposed to cut off during an overdraw situation, but I'd probably buy a AC to USB adapter (like for charging a cell phone) and just plug any of these kind of gadgets into that.