So I'm having a bit of a heat issue with my current machine. The issue is most prevalent when I'm playing more demanding games, such as, Crysis, BC2, and BF3. the problem seems to be with my CPU temperature. On average it's temperature reads at around 40c. When gaming for a lengthier amount of time the temperature shoots up to about 49c. It's at about this point that without warning my entire machine will completely shut off; One second everything is all hunky dory, and then, all power shuts off. The only thing I can do to stop it at the moment is shove a big box fan next to my tower; that usually keeps it at around 45c.

does anyone have any recommendations on a new cooling system that may solve this problem? my current system specs are as follows:

Motherboard: Asus P6X58D-E
CPU: Intel Core i7 950 (4x 3.06GHz/8MB L3 cache)
CPU cooling: Liquid cooling system, with 120mm 2800 rpm fan
Case cooling: Two standard 120 mm fans at 1600 rpm
GPU: GTX 460 1GB soon to be GTX 570
Memory: 6 GB DDR3-1600
Power supply: 700 Watt (no cooling)