Some manufacturers make synthetic wigs that are somewhat heat resistant.
You can use a blow dryer and curling or flat irons on them, but only on a lower tempature setting, usually no hotter than 300-350 degrees.
Although heat friendly, they do not act the same as human hair. When curling you have to slide the hair off the iron maintaining the curled position and then clip in place and allow it to cool completely. This can be a pain in the neck and must be done carefully and evenly.
I usually have clients have me curl or straighten these wigs for them. And I don't recommend changing from straight to curly or curly to straight more than once or twice because it will shorten the life of the wig.
This feature does alow you to customize the wig to the amount and size of curl you want, just don't think you're going to be able to switch from straight to curly and back easily or too frequently.
Once you do heat style your wig it will keep the form even when you wash it.
So even though these heat friendly wigs are great in many ways, they do have their limitations. You really have to be careful with the tempature of the iron you use, I have ruined a wig by not realizing my flat iron was too hot and the hair just came off in my hand when I tried to slide my iron down the section (an expensive mistake!)
Treated with care and handled properly these wigs can be awesome, but I wanted to let you know about the different qualities of this type of wig.
Hope this is helpful, John