#1) Set The Temperature Too High
Most people think that the higher the heat setting on your flat iron, the straighter the hair will be. This can cause you to turn the heat up to a setting that is higher than what is safe for your hair.
You should choose a heat setting based on your hair type.
If you have fine hair, the highest temperature setting you should use on your flat iron for a silk press is 350 degrees. If you have medium hair, you can go up to 375 degrees. For coarse hair, set your flat iron to 410 degrees.
Any temperature higher than this may lead to heat damage.