Not necessarily, warm water (not very hot) should be used before cleansing your hair at the beginning of a hair wash. This is because warm water helps the hair cuticles, and pores on the scalp to open up, allowing your shampoo to remove any dirt, sebum or build-up from the scalp and hair. When it comes to rinsing out conditioner or a hair mask, try switching to cold or cool water, as this will help to seal the cuticle and lock in the moisture from your conditioner. This helps leave your hair looking more hydrated, frizz-free and shiny.