A test which overheats a laptop

[elena09]

I need to test a laptop before buying it. My intention is to see if coolers work well.

Could you please recommend me a good test (up to one hour length) which could really overheat any laptop ?

Thanks. Elena.

[Michael]

phoronix-test-suite default-benchmark graphics-magick c-ray unigine

or just:

phoronix-test-suite benchmark stresscpu2

if just interested in the CPU.

[elena09]

What does the first test?