People "are going to freeze to death" due to a lack of heating after several days without power following Storm Darragh, a councillor has said.
Iwan Ward, a councillor for Boncath and Clydau in Pembrokeshire, said residents had been without power since 02:00 GMT on Saturday and warned it would not come back until 22:00 on Thursday.
Thousands of people are still without power three days after the storm hit.
The National Grid called it "the biggest storm our region has faced in decades".
Ward said people were going to die "not directly because of the storm, because of the lack of electricity, the lack of heat and then lack of food".
"We need priorities for hospitals, schools anything like that but we've also got people out in the countryside who are freezing to death, I'm sad to say," he said.
"People are going to freeze to death, it saddens me to say it but I fear it's going to happen and we need things in place."
According to National Grid, there were almost 14,000 homes in mid and south Wales still without power on Tuesday morning, while Scottish Power said there were still 4,000 outages in mid and north Wales on Monday night.
Openreach confirmed about 6,500 customers across Wales had their internet service impacted as a result of Storm Darragh, with 40 telegraph poles and 50 overhead cables coming down in the high winds.
In Heol y Glyn, near Cymmer, Neath Port Talbot, people said they had been without power since Friday.
Charlie Price, 67, said the situation was "terrible" and he had taken his "ruined" Christmas food to the dump.
"I'm a pensioner, I can't afford to lose that," he said.
"National Grid should have fixed this by now. Or they could have put a generator up here. It's disgusting, I'm furious."
His next-door neighbour, Carl Glave, said surrounding villages still had power but he had "absolutely nothing".
"I'm only just coping because I've got a log burner in one room but the rest of the house is freezing."
Meanwhile, sisters Nina and Terri Camplin said they were "distraught" but trying to support neighbours.
"It's freezing but we miss the light because that goes by 16:00 and candles don't give that much light.
"We're eating cold food as well because we don't have gas and we've lost all the food in our fridge and our freezer.
"It's like being back in the war."
A leisure centre in Llandysul, Ceredigion, has offered its facilities since Monday morning.
Calon Tysul said on social media people could shower, charge their phones and get warm drinks,
Martin Spencer from the leisure centre said about 25 people had used the services.
"The smaller communities have been really affected by the weather. I only got power back at 03:00 this morning so we didn't have any for three days."
He said services would be offered until the end of the week.
"We were lucky that we didn't have any storm damage, so we stayed open not just for our members but also as a safe haven for anyone."
Alun Jones, 82, from nearby Henllan has been without power since Saturday.
He said "it's not very nice" and "quite difficult" to be without electricity.
He relies on torches for light when the evening comes, adding he goes to bed early.
Mr Jones said nobody from any authority had come to visit him since he lost power.
Roisin Quinn of National Grid said its engineers and support teams had been "working around the clock to maintain power across the network".
She thanked customers for their patience, adding the team was "doing everything we can to get power restored across the region as soon as possible".
The Porth Wen Solar Farm in Anglesey was also damaged in the storm, with repair work and the replacement of damaged panels is expected to carry on into early next year, EDF Renewables UK said.
"We are currently assessing the extent of the damage and conducting a controlled clean up," it said.
"Once the initial recovery efforts are complete and the damage is fully assessed, we will carry out a full investigation and when safe to do so, resume generation."