I'm sure there are benchmarks out there that comprehensively cover thermal behavior of laptops, but many sadly don't. I've had many laptops with great benchmarks that completely fall apart under prolonged load (>1 hour) Usually because the benchmark was 10-30 mins, during which the other components didn't heat up enough for throttling to occur.

I don't think the average laptop user should need to concern themselves with acquiring the necessary knowledge to discern good laptop benchmarks.