GPU's can be killed by running at 100% for a long time, that's why graphic cards from miners are mostly dead on arrival.
Too even see the behavoiur of the graphic card running at a 100% you need a second monitor or some monitoring program like RiverTunerStatistics.
Even with a single monitor you can check the utilisation of the GPU by the game if you open the Taskmanager and leave it open, to record the last minute usage, switch into so the game and then switch back to the Taskmanager to see the utilisation.
It will go down if you observe it that way, cause the game stops execution, when it's not the "focused application".
To just be on the safe side, don't play the game in fullscreen at the moment.
And even if the game is windowed I would check the usage with the Taskmanager at some free space of the desktop just to be sure, cause not every card has the same behaviour. And not every operating system is set up the same way.
Edit: And the explanation for why it could kill a graphic card is simple, if the game runs uncapped your graphics card tries to push the FPS at it's highest rate, smaller images (which pixel graphics tend to be) can be rendered by your graphics card so fast that the usage goes unnecessarily high (depends still on possible bottle necks like CPU) some electronical components can be damaged in the long term. One of the first things some can notice is coil whine, where you hear pretty high frequent sounds (if you can hear them, not all people can and not every card produce hearable coil whine on high usage)
Edit 2: And if your card is generally more capable than mine like the one of
coslng it may not even be running at 100 %
But since atleast it could happen, I mentioned it, not a gurantee though
