An example of where I think the noise is temperature dependant,
some of the shots I was thinking about in america were taken at 1600ISO V dim light, on a 28-135 Canon IS, maximum aperture, at around 50mm. A lot of noise, red/blue pixels. Camera had been on my chest, walking around all day, so kinda shaded by my head.
Yesterday, I tested with 1600ISO, in a room without windows, door semi closed, with the 70-300mm Canon IS, 70mm max aperture (4.0). In this shot, there is grain, darker pixels next to lighter pixels, but not what I would call noise, incorrect colours)
Have been looking for a good example where the noise at 400 is greater than it could/should be, but have so far not found one that I have kept