Myth 3: A cold rinse adds shine
This myth has some truth to it. Hair cuticles, which resemble shingles on a roof, lie flat when splashed with cold water. As a result, the smoothed cuticles reflect more light, making hair appear shinier and healthier (hot water leaves it rough and lackluster). The effect is temporary, however unless you dry and style your hair properly. To get your locks to cooperate, seal damp hair with a silicone-based serum, then blow-dry with a nozzle attachment, keeping the airflow angled down the shafts to smooth the cuticles.