When it comes from the boring chore of blow drying my hair in the morning, I want to get the job done as fast as possible. If I were a better person, maybe I would use this time standing wet in front of my bathroom mirror to recite positive mantras or pray, but instead, I spend it flipping my hair around and trying to think of ways to cut the time down as much as humanely possible.

It's probably why the cool air button on my blow dryer goes virtually unused. To me, heat means the whole experience will be done faster. But it got me thinking (hey, I am just standing there), what exactly is that cold air good for anyway? (Besides a cool blast of blessed relief after a sweaty SoulCycle class.)

---

Experts In This Article

---

To find out, I reached out to hairstylist extraordinaire Ashley Rubell. "Hot air is used to alter the hair," she explains. "Hot tools change our texture from straight to curly, or curly to straight." This, she says, extends beyond straighteners and curlers; it includes blowdryers too. "Temperature should really vary according to your hair type," she adds. "If you have thicker, coarser hair you’ll need a higher temperature to work your strands, but with finer hair, or damaged hair, you want to keep your heat on a lower temp."

Celebrity hairstylist Bridget Brager adds that while blow drying your hair with hot hair may be faster, the heat can be damaging, and using cold air is actually healthier. "Styling hair at a lower temperature is imperative to maintain hair health," she says.

Related Stories

Yes, but...time! Brager totally gets that, which is why her go-to dryer is the Bio Ionic’s GrapheneMX Professional Dryer, which has an even warm temperature; not too hot, not too cold. "It's infused with graphene, referred to as the ‘game-changing material of the future’ and the world’s best heat conductor," she says of the hair tool. "I can style at a lower temperature which leaves my client’s hair healthy and noticeably more moisturized."

Rubell says that cool air helps keep hair the way you want it. "Cool air is used to literally cool the hair down and lock that newly manipulated style into place," she explains. "It not only seals the cuticle of the hair shaft but can give a smooth, shiny finish, especially when used with the appropriate brush." It almost serves as a lightweight hairspray in that it helps this new shape stay in tact.

So there you have it: Hot air alters hair, while cool air can help set your hairstyle—and also protect fine hair from getting too damaged. Aren't you glad I had nothing else to think about while I was doing my hair this morning?