[r0l1]

Use a Portal case with heatsink. You'll find some cases on amazon.

[Tempest1981]

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

[bombcar]

I assume that’s iPhone correction of portable. Look for a metal case that directly contacts the NAND.

[r0l1]

That's the model I use: https://www.amazon.de/dp/B07NCMHG5H Hope that helps!

[alecco]

Some aluminum enclosures have fins. But an external enclosure with an actual heatsink would be much better.