This post was originally intended for professionals, and has been viewable only to subscribers that were verified as licensed cosmetologists or cosmetology students since May 2013.

I decided to unlock this content because our clients can benefit from this information too!

bleach-and-heatBleach and heat…the never-ending controversy among stylists nationwide. We all have a different opinion and sometimes manufacturer directions aren’t even taken into consideration when choosing what path to take during a chemical service.

Should I pop Ms. Highlights under the dryer because I’m slammed and just don’t have the time to wait? Absolutely not!

Using heat can mean going from hair that’s manageable to no hair at all! It’s a hairy life or death situation when it comes to the question of bleach and heat…and yes, it is nearly that serious. Do I protect the integrity of the hair or blast it with heat and leave it damaged and lifeless for the sake of staying on schedule?


Whether you’re a stylist or a student you should always be asking yourself those questions when deciding if heat is an option. Don’t let lack of time or another stylists’ opinion skew your thought process. Just because everyone’s doing it doesn’t mean it’s okay!

If you’re a student it’s important to learn why using heat with bleach is a big deal. I’d rather learn from someone who’s done it than from several mistakes that could have been avoided. In school the main focuses are technique and formulating for the clients needs.  I was slow at foiling so my learning leader would say- “Okay hun, get her under the dryer so we can speed this up and leave on time.”. They were more concerned with me getting it done, and placement was the key where heat was portrayed as no biggie. Come to think of it…I didn’t even know why I shouldn’t do it…I just did.


I’m willing to bet that those of you who regularly use heat don’t even think about it. For you, it’s just part of the routine and it says one thing about you as a stylist- You’re not concerned about what can happen to your clients hair…until something happens. Even when it does….when you go to rinse and your foil packets are just coming off….you’re saying “oh sh*t” for yourself, not the client. You’re worried because you screwed up and now you have some explaining to do…but not because you care about what she’s going to look like at work tomorrow. It’s time for all stylists to start making decisions because you care about your client, and stop over-processing their hair because you’ve become complacent and know a healthy trim will camouflage your mistakes!

Salons don't look like this anymore....perhaps there's a reason!  Dryers were invented to DRY hair...

Salons don’t look like this anymore….perhaps there’s a reason! Dryers were invented to DRY hair…

I used to be guilty of using heat when I may not have needed to. I thought nothing of it and neither did anyone else I worked with. There were even some stylists that used heat on each client…every time! I’ve personally seen someone go to rinse, grab a foil, and it just came off(with the hair). She looked at me and she had “oh sh*t” written all over her face. To make it more clear….she barely touched the foil packet and it broke off at the root. That means all the hair in most of the packets broke off, or will at some point. I hope I never see that again, and for those of you that haven’t I hope you never do!


I get looks sometimes…from stylists that just put their client under the dryer and here I am saying, “No, I’m not going to use heat on you because it will damage your hair!”. Who cares if a fellow stylist gets caught using a potentially damaging shortcut…you should always make decisions that you feel are best for your client. In this case opinions can always be argued, but it is up to the other stylist to explain why their way is right for their own clients’ situation. Don’t ever worry about what anyone else is doing…we have all been taught different methods with different products for various reasons. Remember, if you’re doing the right thing for your client and being sensitive to his/her needs/wants…no explanation needed :).

The Pros of using heat with bleach:

  • Faster lifting/processing time
  • Breaking past the “stubborn” stage without reapplying

The Cons of using heat with bleach:

  • Results in unnecessary damage to the hair
  • Causing the hair to simply break off
  • Risk of provoking chemical burns on the scalp
  • Risk of heating the wrong chemicals

A few things to consider:

  • Manufacturer instructions….don’t take their word for it.
  • Dryers emit uneven bursts of heat.

Questions to ask yourself:

  • What was the damage level of the hair when your client arrived at the salon?
  • How will the chemicals I’m using affect damage and porosity levels without heat?
  • Do I feel that it will be risky to use heat given the situation?
  • Am I choosing to use heat because I don’t have enough time to wait?
  • How will using heat affect the other chemicals I’m using(if any)?
  • Am I choosing to use heat just because the directions say it’s okay?

Alternatives to using heat:

1) Use different formulas throughout the application.

I always consider how long the product will be processing on each area of the head. If you’re doing a full or partial foil this is important. For example, I may use 10 volume where I start and switch to 20 volume halfway through(or 10 on bottom, 20 on top). This eliminates the need to “speed up” the last section of foils you did. One of my biggest pet peeves is seeing white and gold highlights because of poor planning! Why do some stylists think this is okay?

2)Use volumes of developer that fit your skills and experience.

If you are uneasy about your speed and foiling abilities I would suggest using the lowest volumes possible for the level of hair you are working with. Don’t use 20 or 30 volume all over on a full foil…..that’s what gets a lot of people using the dryer…..you have to catch up the last section that was applied. Even if you “catch it up”, that last section will still be a different color than the first!


I challenge everyone, students and stylists, to stop and think before each time you want to use heat. Considering the effects and other options first will guarantee happier clients with healthier hair! Always ask yourself- if my hair was in the condition of my clients would I do this to my own hair? If you wouldn’t….you need to find another solution, or live with a guilty conscience!

About The Author

Erika

Professional Hairstylist | American Board Certified Haircolorist | Makeup Artist | Beauty Blogger

6 Responses to Bleach and Heat

  1. Mosa says:

    I discussed with the stylist (GH) about how I’ve been getting my hair bleached for about 3-4 years now and I am very proud of how I maintain it, using minimum heat, only washing once a week, and using highly-rated moisturising shampoo and conditioner. I mentioned a few times that my hair is in such good condition due to me not applying heat regularly (oftentimes, I wash it and let it try naturally).

    When GH was applying the bleach to my roots, she was meticulous – I noticed her using a little tissue to wipe off any overlapping bleach. However, once all the bleach was applied to the hair, she put a plastic cap on and placed me under heat. The common opinion of most stylists is that heat should rarely be applied to hair during the bleaching process, and NEVER on already-bleached hair. I have researched this and found a fair few articles where the common theme is that heat should only be used in very extreme circumstances – i.e. where the hair is really dark or doesn’t lift very easily. This has never been the case with my hair.

    I have never been placed under heat during any other bleach regrowth treatment I have received.

    I was initially placed under heat for 15 mins. Once the timer on the dryer went off, a junior stylist, Madison, came along and checked on the progress. She proceeded to add another layer of bleach over all the regrowth. I did not witness any conversation with GH about what volume of bleach was already on, so it is very possible that a different mixture could’ve been applied. She was not as meticulous as GH had been. There was no care taken to prevent any overlap. I was then placed back under the heat for a further 15 minutes.

    When the second timer went off, I was taken to the sink for the bleach to be rinsed out. I was shampooed and toner was applied to my hair. I was then taken back to my seat and heat was applied for a THIRD time for another 15-minute period. This has NEVER happened in any salon I have ever attended – there is simply no reason to put toner under heat. This is a process that is usually undertaken at the sink.

    So, after me telling the stylist at the start of the appointment that I was very careful with my hair and didn’t apply much heat, and reiterating this multiple times, to preserve its condition and integrity, I was subsequently put under direct heat for 45 minutes in total, with chemicals on my hair. I know from talking to other stylists that this is most definitely not the way to protect and care for someone’s hair. All the evidence I have found online also points to heat not being required for the bleaching part of the treatment, and most definitely not required for the toning/glossing stage.

    Once the toner was rinsed out, and my hair was washed & conditioned, I was returned to the seat where the stylist (GH) proceeded to DRAG the hairbrush through my hair with such force that my head kept getting pulled back. There was no oil applied at this stage, no leave-in conditioning treatment, nothing. I could tell by the sound that her brush was making that my hair was snapping into smithereens. When I condition my hair at home, I can brush a comb through my hair with no effort and no dragging; I put this down to the care I have taken of my hair, and the high-quality products that I use – Redken All Soft Shampoo & Conditioner.

    The stylist (GH) dried my hair using a low heat on the hairdryer, without applying any heat protection, gave it a quick dry trim (as I requested) and then gave it a quick going-over with the straighteners, again without applying any heat protection. It was the only time she seemed reluctant to apply heat – potentially as she had now seen the damage that had now been done and didn’t want to worsen the outcome. She then quickly smoothed some oil over the hair and I was ready to pay and leave.

    I left the salon and went home, where I got on with my day – making dinner etc. Later that night, at bedtime, I was giving my hair a quick brush and as I brushed it back off my face, I burst out crying – my hair was destroyed. My hairline looks like it has been cut with clippers, I have “unwanted” layers in my hair where the hair has been snapped off, and I feel like I have lost about 50% of my hair – it’s straggly rats’ tails now.

  2. Susan says:

    I recently moved and had to find a new stylist/colorist. I went to one recommended by a friend. I get a root touch up as well as high/lowlights. After the foils were put on, she’d put me under the drier before shampooing. I’ve never had that before and didn’t question it (big mistake). I started getting bumps on my scalp and at the hairline. I asked her what I should do and she said I should wash my hair every day (which I always do or it gets greasy/stringy because it’s so fine). I finally thought about what she did different than was done previously. It was the drier with the foils on. I looked online and found some shampoos to help relieve the symptoms (bumps on scalp) of the damage she did to my hair/scalp. It’s almost 100% better (yay) and I found another colorist/stylist that doesn’t use the drier and uses all organic products. I had an appointment scheduled with the one that did the damage. I called after hours to cancel and just said I was going in a different direction with my hair care. I debated giving the real reason but I figured it wouldn’t make a difference in how she ran her salon. I’m just appalled that a so-called professional would take shortcuts that can damage a client’s hair and scalp.

    • Erika says:

      I’m so sorry this happened to you! It sounds like you definitely experienced some chemical burns. Permanent hair color should never go under the dryer, but some stylists do it(if they are unexperienced/uneducated) to process the highlights faster.

      Not only is it bad for your scalp where the permanent color is applied, but it’s awful for your highlighted hair! Speeding up the oxidation process causes a lot more damage than letting the hair lift in the proper processing time.

      Lastly, I think you should have told that stylist why you didn’t want to go back to her. I find it really hard to believe that she didn’t know you had chemical burns(she was probably just trying to get you out the door and hoping you wouldn’t notice). It’s possible that your stylist was just very green and had never made that mistake before, but it’s unlikely.

      Some stylists take these shortcuts because their coworkers tell them “it’ll be fine” or they don’t know any better. There are many reasons why this happens- it doesn’t mean it’s right, but I can see how this confuses/angers many salon clients who have had a similar experience!

  3. Aminat Danmole says:

    Whew! Am I glad I found you! Quick question: I have relaxed hair since I was 14, and I’ve been getting highlights with *no* problem for at least 20 years. This last time my stylist was running behind schedule, switched from a high-lift blonde color (I’m a level 2, for the past 5 years I have gotten chocolate balayage) to a bleach powder in the same line, and then put me under the dryer. I got a chemically-induced bob 2 weeks later. Where do you think things went wrong this time? I was surprised she hasn’t adopted the use of a bond-builder – especially for bleaching her relaxed clients. I’d love your expert opinion, so I know what to look for when I find another stylist.

  4. […] the dryer for excessive amounts of time with color or highlighting services. Check out my post- Bleach and Heat for a more in-depth explanation about what happens to your hair when heat and peroxide are […]

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