Temperatures encountered during blow-drying, flat-iron straightening, and hot curling processes can be high enough to cause severe trauma to the hair. Results of this can include cracks in the cuticle layer, bubbles or voids in the cortex, frayed and split ends, chipped and ragged cuticles, faded color, diminished curl and increased frizz, and broken strands. If avoiding high heat styling methods is not an option, it is important to take precautions to prevent or minimize damage. There are a number of products on the market advertised as heat protectant sprays, lotions, and serums which claim to prevent or repair the detrimental effects of high temperatures on hair. While they protect your hair from the effects of heat, they can never give a 100% assurance for the same.
Thus, its always advisable to avoid as much as you can to bring your in contact with heat. Here is a way to Straighten your hair without any technical appliance. Though the process is a little long but will always be better than the ill effects of Heating appliances.