If you order a unit and select Wavy or Curly texture – that is a processed texture that is put into the hair with a perm for the wave or curl. It should not be hot curled or flat ironed as it may over process the hair since it has a permanent perm already put into the hair. The only units that can be hot curled or flat ironed are the Straight hair textures, Yaki Hair texture, or any unit that states that it is naturally curly or wavy.