As others have asked, desktop or laptop
But also where is it? If it's a "desktop" but on the floor in a deep carpet, tucked against the dark corner of the room under a desk, that's not going to help... bring it out into the air...
And for a laptop... lift it off the desk
I created an MDF raised deck for my laptop, with a massive slot where the fan intake is underneath, that really helped it breathe.
Looking to the future, if cooling is going to be a problem, I like to over spec' the equipment and underutilise it - it's better to run something twice as powerful at half the load... this knowledge came from the hifi world.

