If you have curly hair and you're constantly fighting frizz, maybe the problem isn't the hair - but the water. Hairdresser Alberto Serdan says one habit ruins curly hair more than anything else: washing with water that's too hot. And most of us do it every morning without a second thought.

The reason lies in the nature of curly hair. It's drier by nature, because the oils from the scalp struggle to reach the full length of the strand. Hot water strips away the protective layers and opens the cuticle too much, leading to dehydration, frizz and loss of curl definition. Instead of cleaning the hair, hot water robs it of the very moisture it needs most.

The solution is simple and free: lukewarm water when washing, and if you can, a final rinse with cold. A cold rinse closes the cuticle and locks in moisture and shine - it doesn't have to be icy, just fresh enough to "seal" the hair. Beyond that, Serdan advises massaging only the scalp, combing the hair while it's damp (never dry), and choosing hydrating ingredients like aloe vera, shea butter or argan oil.

The beauty industry wants to sell you ten products for a problem often solved by a single habit. Before you buy yet another expensive anti-frizz serum, try cooler water first - the cheapest change within reach. Sometimes hair doesn't need more products, just less heat.