Is your computer going to be located in a very hot area with no A/C or ventilation?
Also if the ambient air is hot, how are you going to keep the rest of the computer cool since it will be sucking in hot air from the outside. I imagine both the CPU and GPU will probably overheat under load.
In my opinion, As long as the GPU card can maintain the temperature below the Maximum Temperature while under load it doesn't matter much the ambient temperature. If the ambient temperature is hot but the card still runs below Maximum Temperature it should be okay.
Found this Tom's Hardware Review on the WX7100 GPU card. In one section it talks about the Temperature of the card at 22 degree Centigrade testing. Also mentions high temperature limit. Radeon Pro WX 7100 Clock Rates, Temperature & Noise
Best thing to do is ask AMD Support via Email Support concerning your question. They can probably advice you in what is the best environment to use the WX7100 gpu card. You can open a ticket here for your question : Email Form . This is the best way since they will probably answer you back.