The Mestiza Muse

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Be Beautiful. Be Natural. Be You.

The Science of Summer Hair Care and How to Protect It

Table of Contents

Table of Contents

Learn about the science of summer hair care

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Summers can be brutally hot and humid, with rising temperatures and the sun blazing down on you. And while everyone loves being outside by the pool, beach, or park, the warm weather can damage your hair. During this time, care and protection of your summer hair is essential. 

Solar radiation causes photodamage from sun exposure causing chemical changes in the hair keratin. It causes porousness, leading to frizz, breakage, and hair fall. The pool and beach water are drying. During summer, limited sun exposure, hair covering, and proper nourishment are vital. 

The summer is a happy time to enjoy outdoor activities like swimming, sunbathing, and BBQs. But the hot sun and overall climate can take a toll on your hair. Looking after it is vital. With some know-how and a few care tips, you can keep your locks looking good all season long. 

How Summer Affects Your Hair 

Harsh sun rays strip away natural hair oils, making your hair dry and dull. Chlorine from pool water and salty sea water can cause your hair to become brittle. This can fade or strip away the color from dyed hair. 

Well-established scientific research shows that solar radiation causes photodamage to the dermis cells. Solar radiation can also cause photodamage to hair fibers. This topic is relatively new; therefore, “Solar Hair Protector” products are almost non-existent. 

We will discuss summer hair care tips and how you can protect your hair from photodamage and other chemical agents during the hot and humid summer climate. First, let’s go understand some basic science around this topic. 

The Effects of Photodamage on Hair 

Girl with curly hair sitting outside in the sun.

Excessive sun exposure is the most frequent cause of structural impairment of the hair shaft. The sun emits electromagnetic radiation with various wavebands with various wavelengths and energies. 

The two major bands of these radiations that reach the earth’s surface are ultraviolet and visible. Their wavelength ranges from 100 – 400 (UV) to 400 – 800 nm (Visible). The energy of a wave is directly proportional to its frequency but inversely proportional to its wavelength. 

In other words, the greater the energy, the larger the frequency and the shorter (smaller) the wavelength. UV radiation is highly energetic and can cause sunburns or cancer in various human tissues. Therefore ultraviolet radiation (UV) is more damaging. 

UV radiation is classified into three sub-groups: 

  • UVA (315 – 400nm) 
  • UVB (280 – 315nm) 
  • UVC (100 – 280nm) is characterized by different penetration power and damage to humans. 

Mother nature has its own protection system in place; the ozone layer, which helps with protection against high energy radiation by preventing them from reaching the earth. But with increasing climate changes causing ozone layer depletion, a larger portion of UV radiation still reaches the earth’s surface. 

Just as the sun has the potential to damage your skin, summer can do the same to your hair as well. 

I recently had an interesting discussion with my dermatologist about the ultraviolet rays of the sun. Here’s what he had to say: 

“Fried hair isn’t just a figure of speech. The ultraviolet rays of the sun actually ‘cook the hair shaft.’ The damage is most obvious when color-treated hair becomes faded, bleached, and brassy. Even hair that isn’t colored will suffer from sun-induced stress. Those UV rays dry out hair and rough up the hair shaft’s normally smooth cuticle or outer layer.” 

Human hair is made up of a structural fibrous protein, keratin. Keratin contains various amino acids which tie together to form polypeptide chains. The sulfur-containing cysteine is considered the principal amino acid among all and contributes to the mechanical properties of hair. 

Upon the interaction of solar radiations (UVA, UVB, UVC, or Visible) with hair, various chemical groups of amino acids in keratin may absorb these radiations and undergo chemical changes. 

Scientists have observed a decrease in tryptophan amino acid in hair fibers exposed to solar radiation for a prolonged time. Tryptophan degrades, and hence its concentration decreases. Similarly, another amino acid that absorbs ultraviolet radiation is “phenyl aniline.” 

Solar radiation can also oxidize cysteine amino acid to cystic acid inducing significant hair damage. Increased cystic acid makes the hair more hydrophilic, porous, and frizzy. 

Photodamage follows a free radical reaction mechanism. Solar radiations induce the formation of highly reactive free radicals by breaking the chemical bonds of amino acids. These free radicals are short-lived high-energy species that can react with other free radicals or chemical groups. 

They demonstrate indiscriminate behavior for their reactivity, meaning they can react to anything. The reaction propagates in a cyclic chain mechanism where the cycle continues until the system runs out of reactive species. 

Summer Hair’s Response to Swimming Pool or Beach Water 

Girl swimming under water.

Both swimming pools and beach water contain metals such as calcium, magnesium, copper, etc. 

Swimming pools are disinfected with chlorine, and its residue can stay in the water for a long time. Most chlorine damage to the hair and skin happens while in the pool. Once you get out, the remaining residue continues to be absorbed. 

Chlorine under sunlight can generate chloro-based free radicals that can trigger free radical reactions in the hair (a similar story as described above). 

These free radicals react with hair amino acids and oxidize them, so frequent swimmers in swimming pools have dry, frizzy hair with no shine. Also, free radicals react with the hydrophobic sebum layer of the hair surface and strip it away. 

This causes: 

  • A decrease in hair slip
  • A reduction in shine. 
  • Increased fiber-to-fiber friction makes it more difficult to wet and dry comb/brush. 

Swimmers may also notice a slightly greenish shade in their hair after dipping into the swimming pool or beach water. This is due to copper deposits from the oxidation of amino acids and copper ions. This alters color and may require specific color correction products to neutralize it. 

Damage from Chlorine 

Chlorine significantly threatens our hair and scalp due to its oxidative qualities. Think of oxidation as disintegrating or eating away at an organic matter like bacteria cells in the pool, skin cells, and protein cells that your hair is made of. 

It is an alkaline substance that can eat oils and sebum away from your hair strands and then eat away at the protein fibers. The strands are dead fiber, so they can’t self-repair as the skin does. 

Regular exposure to chlorine water can result in the following: 

  • Discoloration of the hair. 
  • Dry, brittle, straw-like hair that’s prone to breakage. 
  • A lack of shine. 
  • Dry, itchy scalp. 

Summer Humidity and the Hair 

Frizzy curly hair in the sun.

Humidity levels are naturally higher during summer because warm air holds more moisture. Humidity affects your hair significantly more in summer than in any other season, especially in wet summer conditions or around areas nearest to seawater. 

The keratin material in hair can absorb moisture (approx. 31% of its original mass) from the surrounding environment. The moisture uptake depends on the hair’s physical and chemical status and humidity. 

Water uptake follows a dynamic balance system where adsorption or desorption varies according to the humidity conditions. Under high humidity conditions, hair absorbs more water and becomes rough and frizzy. 

In dry summer conditions, hair loses water because the surrounding air is drier, so it becomes rigid and dry. Hair also loses its natural volume, body, and sheen. Both dry and wet summer conditions require proper care and specific treatments to help you manage and style your hair. 

How Hair Responds to UV Rays 

A (NIH) National Institute of Health study discusses how seasonal changes affect human hair growth. UV radiation can oxidize the amino acids of hair and cause permanent damage. Similarly, regular visits to the beach or pool can also alter hair properties

Summer hair has the potential to thrive because the weather creates an ideal environment for your scalp. The warm climate helps keep sebum in a more liquified state so it can slide down our hair strands more easily, reducing dryness and leaving hair moisturized and shiny. 

UVA/UVB affects the scalp and hair follicles differently. The scalp (skin) comprises five layers of scale-like epithelial cells. Exposing the scalp to UVB radiation from the sun can burn a layer or layers of the epidermis, causing the scalp to harden. 

That will not only temporarily block sebum and sweat production, but it will interrupt your hair growth. The shedding and regeneration process goes into overdrive for the scalp to heal itself. This changes your pH level, making your scalp and hair follicles more susceptible to infections. 

UVA rays penetrate the dermis layer, where your hair follicle system is. Over time, UVA waves fry the cells in that layer. So regular exposure to the sun causes these follicles to shrink, and as they do, your hair grows thinner, weaker, and slower. 

Protecting the hair cuticle is essential for keeping the hair shaft’s integrity. Excessive sun exposure is the most frequent cause of the hair shaft’s structural impairment. It includes degradation and loss of proteins and degradation of the hair pigment, especially in lighter-colored hair. 

UVB rays are responsible for protein loss, and UVA rays are responsible for color changes. As darker clothing better protects your skin from the sun, melanin (dark skin and dark thicker hair types) better shields the scalp from UVA/UVB rays. 

They can partially immobilize free radicals and block their entrance into the keratin matrix. (US National Library of Medicine).

How to Protect Your Scalp and Hair During Summer 

In the summer, your hair needs extra TLC to protect it from excessive sun exposure, humidity, and beach and pool water. There are numerous hair care methods. Damage prevention is always best, but treatments and products are available to help. 

Strategies to prevent solar radiation from getting in contact with hair will avoid the damage that the sun and water may cause. Here are some prevention tips and techniques:

Limit Sun Exposure 

Everyone wants to be outdoors during summer. It is the best time to enjoy pool days, BBQs, and gardening. But try to limit how often you get direct sunlight. Use early mornings and evenings to be outside when the sun is not blazing. And only go in the sun when necessary. 

Swimming Pre-Treatment 

Prior to swimming, prepare your hair by soaking it in water. 

Then add a leave-in conditioner/deep conditioner

Hair is naturally permeable to water but can only take in so much. If you thoroughly saturate your hair with water or conditioner before swimming, called hydrophobic coating, your hair will have less ability to absorb the chlorinated or salt water. 

Head Coverings 

Covering your hair is the best way to avoid exposure altogether, especially if yours is chemically treated. A covering to minimize radiation exposure. Examples of head coverings: 

  • Hats 
  • Caps 
  • Scarves 

Try to find UVA/UVB filtered hats or head scarf with an ultraviolet protection factor of 50 or higher. 


Umbrellas are also an excellent shield. A US study published in JAMA Dermatology mentions that any fully-functioning handheld umbrella can block over three-quarters of ultraviolet (UV) light on a sunny day. Black ones do even better, blocking at least 90 percent of rays. 


You might think it’s a good idea to make the most of direct sunlight for sun tanning and glowing selfies, but direct sun exposure is highly damaging to your hair and skin. If you must go outside, find shady spots. Using a tent or beach umbrella at beaches, parks, and pools is best to avoid hair damage. 

Moisturizing Products 

Summer humidity and sweat may seem like extra moisture or hair nourishment is not needed. But these can protect your hair from frizz and harsh UV rays. Additionally, it is much required in areas with dry climates in the summer to prevent dry hair from sun exposure.

Summer Hair Care Products That Protect

Hair products and treatments are essential for protecting the hair from sun exposure and summer climate and repairing the hair from photodamage and swimming water. 

Here are tips and products to care for your hair in the hot weather: 

Oils And Treatments 

  • Use oils like coconut oil, raspberry oil (showed absorbance in the UVB/UVC range for use as a broad spectrum UV protectant), sunflower, safflower, grapeseed oil, etc., or leave-in butter (like Shea butter). My personal oil combination is Righteous Roots Oils. Leave-in-conditioner also works! 
  • Coconut oil is effective for protecting hair from the sun. Coconut oil is the only oil that reduces protein loss for undamaged/damaged hair. 
  • If you’ve had excessive sun exposure, make sure to restore your hair by focusing on hydration and restoring protein with protein treatments

Clarifying Shampoo and Chelation Treatment 

 A clarifying or anti-residue shampoo should ensure no chlorine and salt water residues are left on the hair. Cleansing products with a slightly acidic pH (4.00 – 5.00) can accelerate the removal of residues. 

Chelation is a chemical term highlighting the process of “capturing metal ions.” Cleansing products contain chelants that are effective in chelating metals of calcium, magnesium, iron, and copper and removing them from the hair during subsequent rinse-off stages. 

People frequently visiting the pool or beach (seawater) should use a chelation formulation to ensure metals do not stay on the hair and can cause build-up. 

Acidic Spritz 

The pH is the most important chemical feature of the skin and body. Maintaining the correct pH value of the hair and scalp is essential for the overall health of hair. 

Hair products can control the pH of hair. Use products with a more acidic pH to help the hair’s cuticles lay flat. Rewetting or dampening your hair with an acidic spritz will help to keep the pH from swinging. 

The pH stability spritz has a pH of around 3.5 to 4 and helps re-balance your hair’s natural pH level, ensuring that your cuticles lay flat and smoothed down. This slows down the natural progression to breakage. It also hydrates and moisturizes hair and scalp quickly. 

The Best Time to Use Acidic Spritz on your hair: 

  • After exposure to cold or hot weather.
  • After washing.
  • When it’s is dry and feels brittle.

Hair Care After Swimming

Remove the deposits, especially after being in the pool or beach water. Even with a preventive coating before swimming, prolonged exposure to UV radiation or chlorine water will eventually cause deterioration in hair proteins. 

Vitamin C naturally neutralizes chlorine and is a much safer natural alternative than traditional chlorine removal shampoos. According to the USDA, ascorbic acid and sodium ascorbate (two common forms of vitamin C) will neutralize chlorine (neither form of vitamin C is considered a hazardous substance). 

Drench hair in a neutralizing liquid, preferably vitamin C ascorbic powder and water mixture (it can be used all over your body). Just make sure the vitamin C powder is completely dissolved before using it. (Let the vitamin C sit for 10-15 mins.). 

Follow up with a conditioner/deep conditioner (leave in at least 30 mins.), or rinse with apple cider vinegar as a clarifying rinse (test it to make sure its pH is around 4 because if it’s too acidic, it can harm your hair). Apply a deep conditioner to your hair after washing. 

Care from the Inside 

Prevention and products are significantly helpful in protecting your hair against harsh summer climates, but remember to care for your hair by feeding your body with nutrients from the inside. Drink sufficient water, take collagen and vitamins, and eat a nutrient-dense diet. 


Summer is beautiful for outdoor activities, but it exposes our hair to unwanted solar radiation and chemical agents that induce undesired changes. Summer hair requires special care to minimize the effect of harsh weather conditions. The above tips and methods are a good place to start. 


I’m just a girl who transformed her severely damaged hair into healthy hair. I adore the simplicity of a simple hair care routine, the richness of diverse textures, and the joy of sharing my journey from the comfort of my space.

My mission? To empower others with the tools to restore, and maintain healthy hair, and celebrate the hair they were born with!

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