Wig fibers from EpicCosplay can withstand heat up to 410 degreesF, which means the recommended setting for styling tools should be around 350 degreesF or lower. Of course, these numbers won't mean much if you repeatedly add on more heat to a wig without letting the fibers cool first. 

Let's pretend you set your flat iron to 350 degreesF. You take a strand of wig and straighten it. You then immediately straighten that same part over and over again. The strand is no longer 350 degrees hot, it is now higher than that because more heat is packed on. If it goes well over 400 degrees, then you run the risk of damaging the fibers. 

Start with a lower temperature first. If you still want to increase it, gradually work up to it. If you start to hear sizzling sounds, then that means the temperature is too high and the texture of the wig may change.

When straightening your wig, you can go over each strand once and then do it all over again. This gives the wig fibers time to cool before you run it with the flat iron the second time. 

Overall, what we're trying to say is longer exposure to heat would make the temperature rise in the same manner that fabric would burn if an iron is left there too long in the same spot. 410 degreesF would roughly be the melting point so setting the tool to 350 degreesF should  allow some wiggle room in the chance that the fibers get longer exposure to the heat!