The secret: Rinse your hair with cold water for a few seconds at the end of your shower. You may have heard this tip in passing, perhaps without giving it much thought, but are you familiar with just how important this step really is? 

If not, here’s a quick explanation: Your hair’s cuticles make up the outermost layer of the strand, and they lie slightly over one another—sort of like shingles on a roof. Heat and steam can open up these cuticles and make it easier for moisture to seep in (which is where hot oil treatments earn their acclaim), but if they stay lifted, your strands will be more prone to brittleness and frizz.

Cold water seals down the hair cuticles and helps lock moisture into the strands themselves (plus, it helps the scalp retain its moisture since hot water can famously strip its precious oils). “The cool water temperature closes and strengthens the hair cuticle, which can result in stronger, healthier hair over time,” celebrity hairstylist Andrew Fitzsimons previously told mbg about the benefits of cold showers.

He especially recommends pairing a cold blast with deep conditioning treatments (like hair masks), as you want to immediately seal all of those five-star nutrients into the hair shaft.