it's probably the single fan card.
the problem with it, as well as with other cards that have similar design like EVGA 1060 Gaming, is that the cooler beneath the fan is a simple aluminium block. looks a lot like intel's stock coolers. It simply can not properly handle the cooling of ~100w GPU good enough. Even setting the fan to higher RPM will probably not fix it.
The "liquid cooling" solution is a bit too expensive for this card. you are looking at ~100$ for the bracket like NZXT G12 and some AiO. IMO - this card simply not worth this kind of investment.
What you can do:
1. make sure that the card gets enough fresh air.
2. sell the card and get a better one.
3. get some after market GPU cooler. companies like arctic cooling making them, but they are still 30-50$.