These days, the word on the street in war-torn Syria is that hospitals are best avoided - even if you're injured.
"Sometimes we hear that people feel the home is safer than the hospital," said Mohamed Elamein, an information officer at the World Health Organization (WHO) in Gaziantep, Turkey, close to the Syrian border.
Communities often oppose plans to build a clinic in their town or village fearing it will be targeted, he told the Thomson Reuters Foundation by telephone.
Keeping a standardised track of attacks on health facilities and workers has been a major challenge in conflict zones.
But a new digital instant messaging tool that relies on smartphone application WhatsApp has been developed by the WHO and its partners to detect, verify and log the devastating consequences of such attacks.
It is hoped the WhatsApp-based tool will provide vital evidence for the international community, which in the future could be used to hold perpetrators to account.
Syria has been named the most dangerous place on earth for healthcare providers by a Lancet Commission on Syria report, published in March, which revealed that more than 800 medical workers had been killed since 2011.
Nearly half of hospitals in non-government controlled areas were attacked and a third of services hit more than once between November 2015 and December 2016, according to a separate study published by Elamein and others.
The new tool piloted in Gaziantep by health organisations working in Syria involves a WhatsApp group of nearly 300 trusted contacts on the ground.
After the initial alert of an attack, further details are logged and cross-referenced with a range of sources in a central database.
'Who' you gonna call?'
Mobile messaging is the fastest-growing digital communication phenomenon ever, according to a report compiled this year by the International Committee of the Red Cross.
From the Syrian hospital alert system to refugees who share information about safety at sea, digital messaging services like WhatsApp, owned by Mark Zuckerberg's Facebook Inc, are becoming indispensable in fast-unfolding humanitarian crises.
Their potential is growing every day, experts say, with 3.6 billion people globally expected to use messaging apps by 2018.
In Syria, the WhatsApp tool identified 402 attacks against health facilities and medical workers between November 2015 and December 2016. It is also designed to report attacks on ambulances and patients.
The tool is already being deployed in Jordan and Pakistan, and the WHO plans to roll it out in Iraq and Yemen. The UN agency is also considering its use in other troubled hotspots, including in Africa.
While smartphones are less widespread in Africa, the number of users almost doubled between 2014 and 2016, reaching 226 million.
In Nigeria, South Africa and Tanzania, up to 90 percent of smartphone owners regularly use at least one messaging service, such as WhatsApp or Facebook Messenger, according to a study issued last month by GSMA Mobile Economy.
During the 2014 Ebola epidemic in West Africa, 25,000 people subscribed to the BBC's first "Lifeline" humanitarian service using WhatsApp. It disseminated public information via audio, image and text message alerts to combat the disease's spread.
In Somalia, a country grappling with drought and attacks by the al Shabaab militant group, messaging apps also play a critical role for the diaspora, said Amor Almagro, a spokeswoman for the World Food Programme.
"It's one of the ways by which they stay in contact with their families in Somalia, get news from home and arrange for money transfers through the informal networks," she said.
Fanning the flames
But instant messaging is far from a panacea in crisis zones, and some experts say it can also be used to fuel violence.
In Central African Republic, diamond smuggling gangs are plundering the country's resources and funding conflict by making illegal sales via WhatsApp and Facebook, said a recent report by NGO Global Witness.
Connectivity disruptions are another hurdle.
Earlier last month, Somalia plunged into an Internet blackout lasting more than three weeks, after a cargo ship damaged an underwater cable.
Other countries simply pull the plug. In 2016, 11 African governments suspended Internet connections during elections or protests.
© Thomson Reuters 2017