How to Prevent Heat Damage When Flat Ironing Natural Hair

Summer will soon be winding down and many of us will be breaking out the flat irons for silky straight tresses.  I have shared with my readers and YouTube subscribers the steps I take to make sure my hair gets silk straight HERE. Audrey Sivasothy, the author of The Science of Black Hair: A Comprehensive Guide to Texture Hair Care wrote this article for Associated Content which outlines the steps to avoid heat damage, all while sharing a little scientific knowledge.

Heat is one of those things that gets a bad reputation in the hair care world, and it should! Heat can take a perfectly beautiful head of textured hair and completely destroy it in one bad pressing or drying. Once heat has damaged your hair, there is nothing you can do to permanently repair it. Sure, conditioners and reconstructors work miracles for improving the appearance of heat damaged hair, but heat damage is there to stay.This article will provide an overview of strategies for beating heat damage, and teach you how to responsibly use heat to prevent heat damage.

How Hot is Too Hot?

Before we can prevent heat damage, we need to know the temperature ranges to work within. Healthy hair burns at roughly the same temperature as paper: 233C (451.4F); however, burning or scorching can occur at lower temperatures in hair that has been subjected to other harsh treatments. McMullen and Jachowicz describe how the removal of water in the hair occurs at approximately 50C-120C (122F-248F). Milczarek et. al found thatat near 155C (311F), the hair’s keratin begins to break its linkages and become disordered. At approximately 233C or 451.4F, the hair’s keratin begins to melt. Most thermal styling tools operate in the 100-170C (212-338F)range. Those with thicker coarser hair tend to operate their irons and devices in the 150-170C range, or approximately 302-338F. Although these temperatures are still well below the burning threshold, your hair’s condition can change your max heat tolerance.

Prepare Your Hair for Heat Styling

Heat protection starts well before your flat iron, hot curler, or blow dryer ever hits your hair. Hair is best protected from heat damage when it is properly conditioned with both moisture and protein. Black hair should always be cleaned and deep conditioned well prior to applying any heat source. Prepping the hair with a moisturizing deep conditioner prior to using heat is crucial. Moisturizing deep conditioners with hydrolyzed proteins reinforce the hair by creating important cross linkages deep within the hair fiber. The moisture not only helps maintain hydrogen bonding between keratin proteins, but it also helps absorb and dissipate heat through the hair fiber. Moisture increases the hair’s specific heat capacity, or the amount of heat needed to increase the hair’s temperature, Dow Corning scientists say. Poorly moisturized hair heats rapidly and is damaged more easily. Here, water serves a protective function. Protein allows the hair to retain much of its internal moisture, and keeps the hair’s own keratin structure fully supported.

Beat the heat!: Selecting Heat Protection

A heat protectant should always be used whenever a heated appliance comes near your hair. Not only do they protect against heat damage, but they reduce hair friction ensuring a smooth glide through the plates. What you want is something that will absorb most of the direct heat from your device, yet still conduct enough heat to temporarily transform your hair’s keratin. Silicone based produces like Biosilk fusion, Redken Smooth Down Heat Glide, and Chi Silk Therapy, are great for protecting the hair against heat damage. Silicones have low “thermal conductivity” which is the measure of how fast heat is able to pass through them, according to experts at Dow Corning. “The higher the thermal conductivity, the faster a material will transmit heat” they add. Water and mineral oil have higher thermal conductivities and will allow heat to pass through hair pretty quickly. Low thermal conductivity is needed on the hair’s outer surface, but water’s high heat capacity is needed internally to complement this process and protect the hair fiber. Silicones and water work together to protect against heat damage by slowing the rate of overall heating in the hair fiber. Heating the hair at a slow, uniform temperature is much easier on the hair. Dimethicone is slated to be the lowest conducting silicone (best), followed closely by Cyclomethicone- so look out for these two “cones” in your heat protectant.

[See article for list of other ingredients found in good thermal protectors]

Blow Drying

After applying your heat protectant, allow your hair to dry slowly to prevent heat damage. The point of a blow dryer is to dry the hair quickly, but drying from wet to 100% with a blow dryer can be damaging. Water from washing swells the hair fiber; drying shrinks the hair back to normal size. But rapid drying, especially via blow drying, stresses the cuticle and causes cracking to the cuticle surface. While your hair is at its wettest, blowdry it a little more than half way dry. Next, air dry your hair to complete dryness. Always use a diffuser to avoid direct heat to the hair.

Flat Ironing:

Make sure your flat iron Has Temperature control. Temperature control does not mean “on and off,” or “high and low. ” You want to make sure that your device has a dedicated temperature dial so that you can control the heat. Ideally, you want actual temperature ranges displayed in either Celsius of Fahrenheit. Though there is some contention about whether these temperatures are even accurate to begin with, you know on a mental scale that 200 degrees is a heck of a lot less than 300 degrees, etc. so you can work accordingly on this relative scale. Some flat irons have dials with numbers like 10, 15, 25-and there you’d be using a relative scale which is not too helpful. It is still better to have actual temperature ranges to work with. A setting of 25 could be 250C or 500C for all we know!

Keep your appliances Clean

This is especially applicable to flat irons. Flat ironing the hair with dirty flat iron plates can abrade the hair cuticle. Debris can harden on the plates and drag along the cuticle as you smooth the iron down the

length of your hair causing the cuticle to become scratched, or worse burned. Clean your flatiron after every use.

[See article for references]