Although it seems the topic is a bit debatable, cold to lukewarm water rinses seemingly help to close the cuticle layer of the hair. I started doing cold water rinses when I first transitioned but somewhere along the way, I stopped.
I started cold/lukewarm water rinsing again a little over two months ago and for me, I've seen great results. In addition to adding sheen to the hair, I've noticed my hair seems a lot softer after rinsing in lukewarm water.
When I say lukewarm, I am speaking of water that is not freezing cold but somewhere in between cold that is tolerable and cool. Ninety-nine percent of the time, I'm washing, conditioning and doing my ACV rinses in the shower.
If I'm using a shampoo, I always use warm water followed by a couple of co-washes and finally, an ACV rinse diluted with lukewarm water.
Sometimes, I'll just let my hair run under the cool water before I hop out. Immediately, I can feel a difference in my hair as opposed to rinsing with hot water. It's also highly refreshing for the hair and scalp. When rinsing the hair with warmer or hot water, this causes the hair shaft to swell.
Try this experiment:You will need:
2 spray bottles, one filled with hot water, the other with cool water
Here's What to Do:
Section your dry hair into two sections. On one side, spray the hair with cool water and the other with hot water. Do not touch the hair. Do you see a difference? Does the hair that has been sprayed with the hot water swell or expand faster than the hair sprayed with the cooler water?