Computer restarts during hot days

[MiFam]

Hello everyone, my computer has this problem where it restarts without warning whenever I play game during a hot day. This problem only occurs during the summer. My computer room has no air conditioning so it gets pretty hot, but I dunno if that's the reason for my problem or not.

Components:
CPU: Intel I5 2500k (not overclocked)
RAM: G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600
GPU: MSI N560GTX-Ti Twin Frozr II
PSU: CORSAIR TX 750W 80 PLUS BRONZE Certified
Hard drives: Western Digital Blue 500gb 7200 rpm
Kingston hyperx 120gb 3kSSD
Chassis: Corsair 400R
CPU Fan: Cooler Master Hyper 212 EVO

I looked at the temperature while playing some games, but I cannot get the temperature right when it restarts because I only have 1 monitor and the game takes the whole screen.
The temperature was around:
CPU: min: 35~ max: 55-61~ degree Celsius
GPU: min 35~ max: 70-90?~ degree celcius, but mainly around the 70s I believe

 

[IAmTheTofu]

It's most likely your GPU. Your GPU shouldn't be around 90.

You can run the game in windowed and then record your temperatures.

Try moving the computer to the lowest level of your house that has internet if you can, as you will notice yourself temperatures are different.

Position your case fans so that the Rear and Top fans are exhaust, and all others are intake.

And try to get a desk fan of some sort to blow at the side or front of the case (The side with the fan on it).

 

[MiFam]

I tried playing a game in windows mode and the max temp on my gpu was 78 degrees Celsius and my max temp on the cpu was 58 degrees.
No restarting problem though. I think playing on full screen will raise the temperature but I'm not sure by how much though. So far all of the uncalled restartings were from playing in full screen.
For my case fans, I have one outtake on top, one intake on the side, two intake in front, and one outtake in the back.

Thanks for the reply!