The card is overheating, and moreso, that fact that it has been overheating for a while could very well mean you've lost it. They are right about the information provided by NVidia, but they are misreading it. Again, it's a maximum temp threshold. Yes, GPUs can handle more heat than a CPU, but not by that much, and the closer you get to the threshold the more wear you place on the components. The threshold is just there for the card to say "TOO HOT" and shut itself down as a safety measure, but riding it close will be no different than if you surpassed it.
You may have bad airflow in the PC, or some close obstructions that's preventing proper flow from your GPU fan. The GPU fan itself may even be insufficient (often the stock coolers do end up being subpar!).
You can record voltages and temperatures using HWInfo
and setting it to Sensors only
at startup. We recommend you log two 30-minute instances, one during idle, and one during high load. Send them to us in their default format (CSV) and we should be able to take a look at em. Don't worry if your PC crashes midway, it'll be saved up to that point. If you don't select Sensors only
at startup, it'll just send us a report of all your hardware, which will be pretty pointless.