Someone from CloudyNights forum performed some useful tests of the 6D noise levels at different temperatures at astrophotography exposure lengths. Very interesting stuff, for those who are interested. You can find the images here at the original thread:
http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Number=6402677&page=0&view=collapsed&sb=5&o=all&fpart=1&vc=#Post6402677
One of the very interesting things is you can see how much temperature affects read noise levels. The images are taken at +21°C, +7°C, and -7°C, with exposure times of 300 seconds.
http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Number=6402677&page=0&view=collapsed&sb=5&o=all&fpart=1&vc=#Post6402677
One of the very interesting things is you can see how much temperature affects read noise levels. The images are taken at +21°C, +7°C, and -7°C, with exposure times of 300 seconds.