Thousands of homes in the Falkirk area have spent the night without heat in freezing temperatures after a major gas network failure.
Heaters and portable cookers have been distributed to vulnerable residents and 14 schools and nurseries are closed.
Engineers drafted in from around the country are going door-to-door visiting more than 8,000 affected customers.
They have warned some homes could be without gas supplies until the weekend in the “worst-case scenario”.
Denis Kerby, of gas infrastructure company SGN, said they were working to restore supplies as quickly as possible.
“That might be a couple of days but in terms of getting everyone back on, we’re looking at five days,” he told the BBC’s Good Morning Scotland programme.
“It could be up to Friday, it could even creep into the weekend – that is really the worst-case scenario.”
He said engineers were visiting every home to turn off gas supplies at the meter for safety reasons.
Even if residents have managed the turn off their own supplies, engineers still need to make a home visit.
By the end of Sunday night, they had been to 3,000 homes, according to SGN’s latest online update,.
A problem with a “governor” station which regulates gas pressure in the local network developed at about 04:30 Sunday.
Thousands of people woke up to discover they had no heating or hot water as their boilers shut down.
SGN said homes in Bainsford, Carron, Carronshore, Larbert, Langlees, New Carron Village, Skinflats and Stenhousemuir were affected.
Meanwhile, residents have also been warned to be “mindful” of their electricity use, following a number of power outages in the area overnight.
On Twitter, police said: “Scottish Power is asking people in the Falkirk area is to be mindful of their electricity use over the coming days as there’s increased demand on the electricity network with people using heaters while they’re without gas.
With overnight temperatures dipping below zero, people living in the area are being urged to check on vulnerable neighbours.
Falkirk council said 14 schools and nurseries would not open Monday, with a decision on whether they remain shut on Tuesday to be taken later.
The authority made the Camelon Community Centre available to SGN, which was handing out portable heating and cooking equipment to elderly, sick or disabled customers and those with young children.
A mobile catering unit was also distributing hot food.
Mr Kerby added: “Our priority is vulnerable customers. We are liaising with the local authority and our partners in the community to make sure we can visit all the people who may need that extra bit of help
“We would also appeal to people to be really good neighbours – and please check on any elderly neighbours or anyone in the vicinity who may need some extra help.”
One local resident, David McCallan, told BBC Scotland that his home was like an “ice box” when he woke up on Monday morning, until he switched on a heater supplied by SGN.
“It’s not a great heat but it’s sufficient to keep myself and my wife warm enough.”
Mother-of-four Angelene Perry, who has a nine-month-old baby, said she had borrowed four radiators from a friend and has been given a stove and two fan heaters by SGN.
Customers can request heating or cooking appliances by calling 0800 9121717.