My bad - I should've looked up the model rather than assume you were talking about a naked NVMe drive - but to put my comment another way, I think we should all be treating modern SSDs as devices that need proper cooling, so next time you buy a portable drive, consider either putting one together by buying a metal enclosure (with cooling fins if possible), and put an SSD in it, or else try to find a pre-packaged drive with a metal case.
Use a Portal case with heatsink. You'll find some cases on amazon.
Do you have a model # or more info? Amazon search isn't finding "Portal" (except mid-tower). Google finds a mini-ITX case.
The SanDisk is roughly the size of a credit card, maybe 1 x 5 x 10 cm
I assume that’s iPhone correction of portable. Look for a metal case that directly contacts the NAND.
Ah, thanks. Looks like it may have an actual M.2 inside: