Water too cold for you? Wanna put on that geyser? Think twice. Well, do that if you cannot bear the chill but let your hair experience cold water only. Or better still, alternate your hair wash with hot and cold water, using cold water in the end.
Wonder why there is a cool air button on your dryer? Because cold air, like cold water, closes the cuticle of the hair, locking down the protein from shampoo and conditioner inside your scalp and preventing the dust particle from getting into pores of the scalp. It also makes your hair look healthier and shinier. Also, by closing the cuticles cold water prevents hair from being pulled out while combing.
On the other hand, hot water makes your hair shaft weaker and more vulnerable to dust. Not only that, it also dissolves certain oils, secreted by the scalp, which are good for hair. This causes further dryness. Cold water dos not dissolve these natural oils.
So use cold water for your hair and use that cold air button on your dryer.