By Jc of The Natural Haven
Does blow drying on cool damage your hair?
On a journey to find the answer above I came across a lovely little scientific study (J Soc Cosmet Chem, pp 27–36, 1981) which showed that even with low temperature blow drying hair never gets back to its original moisture level until it is soaked in water then air dried or placed at a much higher humidity.
In other words, heat drying your hair actually does dry your hair out. To explain this, I will start off with a reminder of the basic structure of hair.
This is what happens when hair is wet through washing. Water travels into the cortex.
When hair is wet, there are two options to dry it: air drying and heat drying.