The 6D is a great camera, very straightforward to use and it produces high quality images. However, on a trip to the Amazon, while photographing on a river beach where the temperature was about 35C, my primary 6D body suddenly went crazy. Touching the front dial caused the shutter/aperture settings to cycle constantly, and other settings e.g. ISO just kept changing randomly, without any input from me. After a few minutes the shutter button locked up. I switched off, removed the batteries and stashed the camera in a cool shady cabin, and after 2 days of "rest" it resumed normal functioning.
Meanwhile I had switched to my back-up 6D body, which operated fine for the remaining 3 days of the trip, but the high humidity regularly fogged the viewfinder, despite storing overnight in a sealed poly bag, and giving the camera an hour to "acclimatise" each day before starting to shoot.
A friend of mine who also has a 6D had a very similar experience, with his camera developing a mind of its own and randomly cycling itself through the full range of settings without any user input.
So, for what it's worth, my advice would be to steer clear of "budget" full frame cameras if you need to shoot in tropical heat and humidity. I've since upgraded to a 5DMkiii and 7DMkii, neither of which have yet given me any weather-related problems despite being used in similar tropical conditions in South America, Africa and India.
Meanwhile I had switched to my back-up 6D body, which operated fine for the remaining 3 days of the trip, but the high humidity regularly fogged the viewfinder, despite storing overnight in a sealed poly bag, and giving the camera an hour to "acclimatise" each day before starting to shoot.
A friend of mine who also has a 6D had a very similar experience, with his camera developing a mind of its own and randomly cycling itself through the full range of settings without any user input.
So, for what it's worth, my advice would be to steer clear of "budget" full frame cameras if you need to shoot in tropical heat and humidity. I've since upgraded to a 5DMkiii and 7DMkii, neither of which have yet given me any weather-related problems despite being used in similar tropical conditions in South America, Africa and India.