When it comes to maintaining luxury hair extensions, especially during the summer months, protection is everything. Sun exposure, heat styling, pool chemicals, and even something as simple as your shower water can quietly break down the integrity of your hair. That’s where the L’Oréal Professionnel Metal Detox Leave-In Cream becomes a total game-changer. Why Summer Is Hard on Hair Extensions Extensions don’t receive natural oils from your scalp the way your natural hair does.