Aly Walansky doesn’t care how ridiculous she may look.
When she is running errands or heading to meetings and it begins to rain, she will reach into her purse, pull out her shower cap and place it over what she describes as her “coarse, Jewish Eastern European, curly” hair.
Ms. Walansky spends about $30 a week on blowouts and $400 a year on treatments that keep her hair sleek and smooth. So, even if it’s just really humid out, she will wear a shower cap.
“I’d much rather embarrass whomever I’m with than arrive where I’m going with bad hair,” said Ms. Walansky, a 35-year-old writer who lives in Brooklyn. “Blowouts are expensive.”
Hair-straightening processing like keratin treatments and blow-dry salons are highly popular among women with all types of hair, and this is a summer that at least feels even hotter and more humid than usual. So shower caps and other impermeable head coverings that shield follicles from frizz-inducing elements are coming out of the shower, appearing in social-media selfies and sometimes even on the streets.
On Snapchat a few weeks ago, the model Joan Smalls showed off hers.
In late May, Kaley Cuoco, a star of the sitcom “The Big Bang Theory,” posted a shower cap selfie on Instagram (the image ended up being shown on Entertainment Tonight and in Star Mag).
Felicia Sullivan, a former New Yorker who lives in Los Angeles, has textured curly hair that she straightens two or three times a month by paying $65 for 90-minute blow-dry-and-flat-iron treatments. She too is taking action against the rain, and not just by moving out West.
“Umbrellas never work because, based on wind, you can easily get sprayed, so I’ve been known to carry a shower cap in my handbag,” said Ms. Sullivan, an author who also works as a marketer. “There’s no way I’m ruining my blowout should it start to downpour. No matter where I go, my hair is guaranteed to be covered.”
She knew she could make better-looking caps than what was currently on the market, but she wondered if there were other innovations that could be added to an age-old product. She said she interviewed many women and learned that for younger women, the function of caps was as much an issue as the lack of style.
“Once I started learning about all of the advancements and constructions of active wear and performance wear, I decided that all of this stuff are things that could be applied to this space that had zero innovation,” said Ms. De Jesu, who lives in Brooklyn. Her Shhhowercaps, like the one Ms. Smalls modeled on social media, have a stay-put rubber grip and a breathable antibacterial coating to keep humidity from building up.
In designing the products for the Louvelle Luxury Showerwear line of turbans, Simone Taylor, 33, took inspiration from stars wearing turbans and head scarves, like Beyoncé and Eva Mendes, as well as runway looks created by Missoni and Marc Jacobs.
“I created Louvelle because, like most women, I don’t have time to wash my hair every day and my husband would always make fun of me when I wore my shower cap,” she said. “I wanted to create something that you could look at in the mirror and not feel unattractive in.”
To be sure, there are plenty of people not buying into the idea of wearing anything that looks remotely like a shower cap out of the house. “There are better ways to publicly preserve a blowout,” said David Lopez, a hairstylist who works with celebrities including Chrissy Teigen, like “loose ponytails, soft braids, hair tucked into a hat.”
But Megan Driscoll, 36, of New York said nothing could come between her and her Drybar Morning After shower cap. “I have seen a few people laugh at me occasionally as I’m walking home with my shower cap on, but it doesn’t bother me at all,” said Ms. Driscoll, a marketing and public relations consultant. “The temporary mocking is well worth a week of good hair.”