An emergency government phone alert warning of wildfires across England and Wales put domestic abuse victims at risk, campaigners have told the BBC.
Millions of people's mobile phones lit up and bleeped with a "severe alert" notification on Friday which said there was a "very high risk of wildfires nationally".
But charities and survivors have criticised how a lack of advance warning meant there was little chance to protect those hiding secret phones in domestic abuse situations.
A government spokesperson said the alert was sent "after a direct request from fire and rescue services" and it was working closely with domestic abuse charities for tests of the system.
Most people received the blaring alert at 19:00 BST on Friday - and it came as a surprise given the government had not told people it was coming, as it has done for tests of the system.
The notification, which cautioned against the use of disposable barbecues, naked flames or fireworks, was the biggest use yet of the emergency alert system and Prime Minister Andy Burnham urged the public to take it "seriously".
A Cabinet Office press release, posted to their website at about 18:45 on Friday, was missed by many in the media, which meant there was little warning to the public.
This potentially jeopardised domestic abuse victims trying to hide secret phones they use to seek support and try to escape abusers, some campaigners have said.
Women's Aid, the national charity aiming to end domestic abuse, is calling for more forewarning of alerts wherever possible.
Veronica Oakeshott, the charity's head of external affairs, told BBC News: "Survivors of domestic abuse frequently turn to second phones to help them access lifesaving support or flee from abuse."
It is vital the devices stay hidden, she said, before adding: "We would urge the government to forewarn the public that alerts might be issued, when possible."
It has been reported that senior government figures were discussing whether or not to send the alert hours before, on Friday morning.
The alert came after a spate of wildfires including one that destroyed 19 homes in Stourbridge, West Midlands, on Thursday.
Padua Eaton, 29, a survivor of domestic abuse who set up support group The Harborough Doves, said her "heart dropped" when she received the alert.
"My first thought was anxiety at the alarm - many people in domestic abuse relationships have a secret second phone in order to keep communication with friends or professionals and this alarm would have alerted abusers immediately," she told BBC News.
"The government should have been more upfront about the alarm - telling the press 15 minutes before it went off is poor planning in my opinion.
"Other measures should have been put in place to inform people without resorting to the alarm at such short notice."
She urged ministers to look into silent notifications, warning that "if alarms become frequent, victims may no longer feel safe keeping these phones".
Her concern was echoed by Maggie Evans, director of frontline services at abuse prevention charity Hourglass.
She called for ministers to consult organisations supporting the most vulnerable before future alerts.
"Domestic abuse victims should never be put at risk by the very systems meant to keep us all safe," she said.
Evans said there had been "no meaningful advance warning to frontline domestic abuse charities" and "no targeted safety guidance for victims".
"Effective public safety must always be built on proper safeguarding."
