Friends had warned Yasmine Mustafa about the dangers of touring South America solo. She came home with a notepad full of scary traveller tales and the seeds of a safety invention.
Meet "Athena" - a one-press button that summons help when danger looms, part of a growing market in portable, panic-attack devices tailored for an increasingly dangerous world.
Many are aimed at women at a time when "pussy grabbing" has made headlines from the Oval Office to the casting coach, and after the #MeToo campaign heightened worldwide awareness of sexual harassment and assault.
Mustafa said her customers included dog walkers, nurses, taxi drivers and online daters. "The people that wear it all the time are the people that have been attacked or assaulted," she told the Thomson Reuters Foundation.
Mustafa said the assault stories she had heard from fellow travellers in South America, followed by the rape of a neighbor, were the twin catalysts that pushed her into action.
In 2014, she founded a social enterprise, Roar for Good, and launched her wearable gadget Athena three years later, allowing users to alert chosen contacts if they ever felt threatened.
"Tens of thousands" of Athenas, which clips onto clothes, have been sold, according to Mustafa, with each one costing $80.
The polarised climate - hate crime is on the rise, political rhetoric is shrill and women endure a torrent of abuse from internet trolls - is horribly good for business.
"We got a lot of outreach from women who wear hijabs, women who experienced more street harassment as a result of all the rhetoric that is being shared here in the United States," Mustafa said by telephone from her company base in Philadelphia.
"The emails that we received even mention they've experienced more harassment than usual as a result of our current president."
Roar for Good is a social enterprise - a business that seeks to do good as well as make money - and some proceeds go to charities that run education programmes on violence and abuse.
It is estimated that one in three women experience physical or sexual violence during their lifetime and a poll by the Thomson Reuters Foundation found the United States to be the tenth most dangerous country for women.
Several tech innovations aimed at keeping women safe have come to market in recent years, some invented by women with personal experience of assault. Aside from the sleek buttons - which come in fashionably matt colours - women can also buy keyrings, wrist bands and jewellery that house safety devices.
Sales of such products are set to grow by 13 percent in the next five years, according to analysts Market Research Future.
Wristband SAFER PRO, which sends alerts while recording audio, won this year's $1 million Women's Safety XPRIZE, a global competition for technologies to help protect women and girls from violence.
But a U.S. women's group which works to prevent sexual assault has expressed reservations about the effectiveness of such gadgets, which do not address a wider cultural problem.
Like Athena, attachable safety device Revolar can alert contacts to a user's location so they can send help.
Revolar was founded by Jacqueline Ros, whose sister was assaulted twice, and Andrea Perdomo, whose grandmother was kidnapped by guerrillas in Colombia.
While Mustafa reports that less than 1 percent of users have pressed the button to ask for help, Revolar reports 6,400 red alerts were triggered on the 30,000 devices they sold in 2017.
"We have addressed hundreds of emergencies, but the real key is that on thousands of occasions, every single day, we have help(ed) people connect with those people who are important in their lives," said a company spokeswoman in emailed comments.
Mustafa said her product made women feel more confident.
"It's just like using pepper sprays or tasers. You never know if they are going to be useful, it depends on that moment. We focus much more on preventing something happening," she said.
Kristen Houser of the National Sexual Violence Resource Center, which works to prevent sex assault, said devices were of limited use as they were used when danger was already underway.
"These gadgets don't have any impact on whether or not people in our culture feel they have permission or ability to scare others, whether that's following them, cat calls, inappropriate comments or literally an attack on their person."
More than two thirds of women have been followed, according to a global survey of nearly 17,000 women by Cornell University, and most women experience street harassment before turning 17.
Houser said her organisation has noted heightened insecurity among women since the U.S. presidential election was won by Donald Trump, who had been caught boasting about groping women.
"Whenever you have a prominent person expressing sentiments that let you feel unsafe or like violations of your personal boundaries aren't a big deal, that can make anybody worry - are other people going to follow suit?"© Thomson Reuters Foundation