Are you sure you haven't assigned some strange setting to the front or rear dial? If it were me, I'd check all my settings. If all else fails, do a factory reset. 

It really doesn't tell you anything, your assumption is based on a very scant bit of evidence. I use an A7 IV as my backup and have shot it in much, much colder temperatures than that, well below freezing. I've shot it in rain, snow and brutally hot temperatures, next to pavement that scanned 140°F in direct summer sun. There would be no point in manufacturing a camera that couldn't operate in such normal temperatures. Something else was going on. 

Update: A bit more information. I used both the Sony and Chipfancier CF A cards in the A7 IV while in Alaska in temperatures ranging from high 40°F to low 70°F never below freezing. When I arrived back home I replicated the same setup with the A7 IV & 200-600 f5.6-6.3 Sony lens and switching the two mentioned CF A cards and had no issue shooting on Hi continuous. I tried various other lenses and got the same results. So that tells unless it was a fluke the A7 IV can't operate within the above temperature range.  I am heading to Africa next month and hope I do not have the same issues of the camera hanging up or buffering. I can't think of anything else to try or do.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!