Problem camera internal temperature is becoming too high can't shoot canon 5d mark iii

SOURCE: Konica Minolta Dynax 5D/Maxxum 5D turns itself off after first shoot

It sounds like that's the first black frame problem that is a fairly common defect with the cameras, so much so that Sony is repairing it for free, for more info, see:

http://ca.konicaminolta.com/information/20070202/01_en.html

then go to:

http://eservice.sony.com/webrma/web/index.do to set up for service.

SOURCE: Canon 5D resolution question

The 5D has a 12.8 mega pixel sensor.

2 x 4 ft. is 24 x 48 inches, so you have to cover 1152 sq. inches using 12.5 million pixels.

Spreading 12.5 million pixels over 1152 sq. inches means 10,850 pixels per sq. inch. Taking the square root gives you a maximium resolution of 104 pixels per inch (or 'dpi')

Photoshop will allow you to increase the resolution by a process known as 'interpolation' .. increasing to 300 dpi using Photoshop before printing will give a better result.

NB. Depending on your printing process, you may end up dealing with files up to 500Mb in size ....

SOURCE: Internal Temperature too high to shoot.

This is obviously a problem with the internal parts of the camera. There are too many things it could be to give a definitive answer, and it would be too complicated for an amateur. If you take it into a local camera shop they should be able to run diagnostics on it and replace the problem.
Best of luck to you.

SOURCE: Canon EOS 5D Mark II whrer is the selftimer botton

Self timer function is mentioned on page-86 of manual.
Below image is part of user manual that will help you to turn on self timer.
Thanks.

SOURCE: attach strap to canon BG-E6 and 5D

Cannon lp-e6 battery fit canon eos 5d mark ii http://www.canon-digital-camera-battery.co.uk/batteries/canon-lp-e6.htm