If you’ve got 2 cards in (which you have) it sounds like you’ve got ventilation issues. Either heat build up in case or, and more likely, the cards just don’t have enough air due to their spacing.
Take one card out and see how the temperatures are then, if it’s vastly improved then the card was previously being suffocated for airflow.
Improving that can be awkward, some cooling designs don’t consider having another card close by. It might be a matter of changing coolers or trying to force feed the card/s air.