Using an electric hair straightener can change and damage the structure of keratin fibers in your hair. If you’re trying to improve and increase keratin, blow dry your hair straight on a cool setting rather than using a straightening iron. Bleaching your hair damages keratin and your hair’s cuticles. Using gentle dyes are okay, but avoid bleaching your hair if you want strong, healthy keratin. Protect your hair from those strong summer rays, which can act like bleach on your hair and damage keratin. Wear a wide brimmed hat or cover yourself with an umbrella if you’ll be outdoors.  Fine, light-colored hair is more vulnerable to sun damage than thicker, coarser hair. Protect your skin from sun damage by covering up or wearing sunscreen on exposed skin. Pools and hot tubs contain a lot of chlorine, a chemical that dries out your hair and damages keratin. If you’re going to swim in a pool, rinse your hair well with clean water afterwards.

Summary:
Don’t straighten your hair with an iron. Don’t bleach your hair. Protect your hair from the sun. Rinse your hair thoroughly after swimming.