Guide | July 12, 2024
How to protect hair from heat damage
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In the world of hair care, various misconceptions about hair damage exist, and we’re here to clear the air. Exposure to high heat is a common culprit that can alter the structure of your hair’s keratin strands. The best way to keep hair looking its healthiest is to prevent hair damage in the first place. This includes hair styling that focuses on control with less reliance on heat, along with thermal protection formulations to prevent breakages1.
Ahead, uncover what damaged hair is, how to spot the signs of heat damage and tips for managing and fortifying your locks. These insights will help elevate your hair health and enhance its natural shine.
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What is damaged hair?
Hair damage occurs when the various components of your hair – the cuticle, cortex, medulla and keratin proteins – undergo physical or chemical breakdown. Let’s simplify the science behind hair:
1. Cracks in the cuticle: Damaged hair develops cracks in its outer layer, the cuticle. The cuticle normally shields the inner cortex, which gives hair its elasticity and strength. Once the cuticle is damaged, the cortex becomes exposed, making your hair more susceptible to additional damage and breakage.
2. Loss of shine: Healthy hair reflects light in a single direction, creating shine. However, when the inner cortex is damaged, hair becomes brittle, leading to split strands and split ends. This damage reduces the hair’s ability to reflect light, resulting in a loss of shine.
What causes heat-damaged hair?
Extreme temperature is one of the main causes of hair damage, as it can change the shape of keratin protein strands. At temperatures over 150°C, α-keratin slowly converts to β-keratin, weakening strands.
When the heat goes above 230°C, it starts burning your hair and breaking down those tough disulphide bonds. These bonds are what give hair its bounce, strength and shape. So, when your hair gets damaged by heat, it becomes weaker, less bouncy and more prone to further damage.
Aside from excessive heat, some other causes of damaged hair include:
- mechanical abrasion (brushing)
- chemicals
- UV exposure from the sun.
What does heat-damaged hair look like?
If you’re finding your mane a little harder to manage, this may be due to heat damage. The telltale signs are often obvious – think brittle hair that breaks easily, or more knots and tangles than usual. Other signs of heat-damaged hair include:
1. Dullness and dryness
The hair cuticles contribute to the shine of your hair. When damaged, they can lead to lacklustre-looking hair. Damaged cuticles struggle to maintain moisture, leaving your locks dehydrated and more prone to breakage. Dryness is another factor that can contribute to the overall dullness of your hair.
2. Split ends
The medical term for split ends is trichoptilosis (or schizotrichia). This is when the ends of the hair physically split. Split ends happen when hair becomes dehydrated. The hair becomes stiffer, and it frays. While this typically affects the tips, splits can occur higher up the strand as well.
3. Frizz
Heat damage causes hair cuticles to become more porous and absorb extra moisture, leading to excess frizz. On the other hand, high porosity can also make your hair cuticles lose moisture more easily, resulting in frizz.
4. Flyaways
When used at high temperatures, hot tools strip the moisture from your strands. In this instance, flyaways are typically a sign of breakage. These look like short hair strands that stand up after breaking off near the roots. Taming flyaways can pose a challenge, impacting your overall appearance, especially when aiming for a polished and refined hairstyle.
5. Hair loss
The average person typically has 80,000 to 120,000 hairs on their head, with each hair strand undergoing a growth cycle lasting 2 to 6 years. It’s normal to experience hair shedding during this period. However, heat-damaged hair may lead to increased hair loss during brushing or showering.
Being able to observe signs of heat-damaged hair will allow you to determine how to manage your hair.

How to fix heat-damaged hair
Hair is not a living tissue, so it doesn’t possess regenerative abilities. For this reason, you can’t ‘repair’ damaged hair. However, you can take measures to maintain hair health over time. Protecting strands is crucial for supporting healthy hair and keeping that shine factor high.
Explore the following tips to enhance the vitality of your hair and reduce the likelihood of future heat-induced damage.
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Look for specific hair care products
If you’re dealing with heat-damaged hair, consider making adjustments or additions to your hair care routine. Look for hair care products specifically designed for heat-damaged hair and your hair type, as they can aid in replenishing moisture to hair that has been over-styled. Depending on your hair type and texture, you might also need extra support beyond shampoo and conditioner. For example, wavy, curly or coily hair may require more attention and specialised products compared to straight hair.
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Use styling tools that don’t create extreme heat
Dyson’s hair care products are designed for different hair types to produce no to minimal hair damage. Unlike others, the Dyson Supersonic™ hair dryer measures air temperature over 40 times a second and regulates the heat. This prevents extreme heat damage, to help protect your hair’s shine. High heat can also affect scalp health. Attachments and styling accessories are available, such as the Gentle Air Attachment which creates a gentle, cooler airflow while still drying hair fast, making it kinder to sensitive scalps.
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Maintain a low temperature
Overexposure to high temperatures can weaken the chemistry of hair. Losing strength and elasticity over time can leave it more vulnerable to breakage. To prevent this, you can use your hair styling tools on a lower temperature.
The Dyson Airwrap™multi styler features heat damage prevention technology, where it measures the airflow temperature over 40 times a second, intelligently controlling the heating element to keep the temperature under 150°C. The Dyson Corrale™ cordless hair straightener features temperature controls, so you can turn down the heat for less hair damage2, reduced frizz and fewer flyaways.3
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Style hair once dry
Unless you are using a wet-to-dry styler like the Dyson Supersonic™ hair dryer or the Dyson Airwrap™ multi-styler, ensure hair is completely dry before styling. This is because when you straighten hair before it’s fully dry, moisture particles within the hair strand heat up extremely fast, burning the hair and affecting the cuticle surface, which increases split ends and breakage.
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Limit heat styling and use a heat protector spray
While a variety of Dyson products have been engineered with no heat, it’s advised to prevent heat damage caused by straightening hair (or using other heat styling tools) by limiting your use (for example, opting for every other day or restricting use to once per day). Additionally, when using heat tools, ensure your hair is protected with a heat protector spray. These sprays create a protective film around the hair strands, ensuring even heat distribution and a gentler warming process, so the risk of heat damage is minimised.
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Schedule regular trims
Wear and tear, heat styling or chemical treatments can cause damage and breakage to hair strands, especially at the ends. Regular trims can help remove the damaged ends, preventing further breakage. To prevent split ends from forming, especially if you often experience split ends, schedule a trim for every six to eight weeks (thicker hair types may be able to extend this to every 10-12 weeks).
Although strands can’t repair themselves once damaged, Dyson hair care tools are engineered with intelligent heat control to regulate temperatures, prevent extreme heat damage and help protect shine.
For professional hair care advice and guidance on our entire hair care range, visit the Dyson Demo store.
1Rigoletto, R. et al. (2011). The effect of various cosmetic pretreatments on protecting hair from thermal damage by hot flat ironing, Journal of Cosmetic Science, 62 pp.265-282
2Thermal damage measured by hair strength, when creating an equivalent straight style using minimal heat. Tested on Corrale with flexing plates vs Corrale with solid plates.
3 Direct image analysis vs untreated hair.