external monitor question

[bmms8]

Hi i was wondering what you guys do with your macbook when connected to an external monitor. Do you leave the lid closed or leave it open for ventilation. Please let me know, thank you.

[Chris Rogers]

i prefer to leave open and use 2 displays at once

But doesn't the bottom get hot, i'm typing on it now and my keys are kewl. So, for that reasoning I'd say it doesn't matter.