My daughter, 20 years old - stays in hostel away from us parents. Most probably misguided by friends - she has recently started using heating type'hair straightener to'straighten' her otherwise luxurious and slightly curly hair. I for one - know that this kind of heated treatment is not only harmful to the hair; but also completely unnecessary! She's unable to understand when I explain. Could you please help me by clarifying if this is really harmful or not. - and by listing the ill-effects of this - technically and scientifically. Thank youA worried parentRajeev B AgarwalChennai.