it’s a basic engineering problem. as you put more functional stuff into a smaller space, you get more excess heat. there are workarounds to deal with overheating, but the problem is always present (unless there’s a radical change in technology). this is why computers and game consoles have built-in fans, they would overheat and shut down otherwise.
I’ve had the same issue with my 128gb sandisk ultrafit. the metal gets burning hot when I transfer gigabytes, and even when I leave it in without doing anything, it’s hot right after ejecting. it makes sense actually, because they maximized efficiency - with as much speed and memory in as small a space as possible, there has to be a tradeoff: excess heat.
I’ll assume on good faith that sandisk is aware of this, and that QC determined that the excess heat is not enough to cause damage to hardware. But naturally it’s alarming to the end-user, and I wish they’d been more up-front about this.
In the meantime, I’ll still use it, but I’ll limit my usage to be on the safe side. It seems to especially heat up in my laptop. I’d think adding ventilation holes would’ve helped but there could be design reasons I’m not aware of.