Unlike with car batteries, there is no coolant running between the 18650 cells in a 5 year old laptop.
Standing air does not provide any cooling.
All modern laptops use Lipo packs instead of cylindrical cells for space savings and more capacity.
This is not the reason why macbooks have such long battery life, since there are other laptops with short battery life that also use lipo cells, so in that sense he is wrong.