I leave civ and PC run idle - civ crashes

[V. Soma]

I don't know if this belongs here but I would welcome an answer to my problem:

Whenever I have Civ5 running and I leave my PC running idle with civ5 on,
I come back to my PC after - say - an hour,

I find that civ has crashed,
and PC had to reboot...

What could it be?

 

[Skwink]

Could it be overheating?

 

[V. Soma]

Could it be overheating?

Hm, thanks, I will check that...