Need an answer quickly please.

Before i go to bed, I was going to download a demo, fresh to play in the morning when i wake up.
however, I'm a bit worried about leaving the 360 on all night.
Now, i assume that when the screen goes dark after about 10 minutes of letting it sit there that means its in low power mode?
will this guarantee that it wont overheat?

also, my room is pretty damn cold (its winter over here in Australia)..

You can set your 360 to let it download while teh 360 is in "sleep mode"

Also even if you did not set it like that dont worry, its on dashboard and uses no energy for that.

..... my room is pretty damn cold (its winter over here in Australia)..

DevilsDontCry13

then it'll be ok.

i have left my system on for a week during this summer and nothing happened yet