Thousands still lack power or heat after Sandy but elsewhere city's schools and subway lines are almost back to normal

New York City mayor Michael Bloomberg promised Monday that all New Yorkers still without power following superstorm Sandy would be found warm shelters ahead of a new storm hitting the city later this week.

Overnight temperatures are set to drop to near freezing levels on Monday night, putting in focus the plight of up to 40,000 people in New York who need refuge from the cold amid ongoing power outages.

Bloomberg said the city had adequate shelters to accommodate all those in need, and that every effort was being made to ensure that elderly and vulnerable citizens were able to find shelter in advance of Wednesday's nor'easter – which could dump up to four inches of rain on the region.

The evacuation comes as much of Manhattan began to get back to business as usual on Monday.

With power restored to lower Manhattan and 94% of schools open, the city's network of subway lines were full with commuters and students as it operated a revised timetable.

But further afield concerns were more grim. In the Rockaways – a coastal region in the borough of Queens – thousands of residents were without power for the seventh straight day.

With temperatures dropping and a powerful new storm due to hit mid-week, city officials are facing an uphill battle to find alternative accommodation in a city where spare housing is scarce.

On Sunday, Bloomberg said between 30,000 to 40,000 New Yorkers may need to be relocated as they could be without power for some days to come.

"We're not going to let anybody go sleeping in the streets … but it's a challenge, and we're working on it," he said.

Governor Andrew Cuomo was likewise frank with his assessment.

"People are in homes that are uninhabitable," he told reporters at a press briefing. "It's going to become increasingly clear that they're uninhabitable when the temperature drops and the heat doesn't come on."

One option could be setting up mass trailer camps, similar to those that existed in New Orleans in the aftermath of hurricane Katrina in 2005.

Of those that need temporary resettlement, it is thought that 20,000 currently reside in public housing.

In an update Monday, Bloomberg said there were adequate numbers of shelters to accommodate those in need.

"Every New Yorker who needs a warm place to live and a roof over his or her head is going to have one," he pledged.

"We have to go down to an even more micro level and make sure each individual gets the services they need," Bloomberg added.

The incoming storm made the work of emergency teams "more difficult and more urgent" the mayor said, adding that housing everyone would pose a "big challenge".

The nor'easter could bring gusts of up to 55mph and further flooding.

"Prepare for more outages," was the advice of National Weather Service meteorologist Joe Pollina. "Stay indoors. Stock up again," he added.

The immediate concern facing those in cut-off areas is how to keep warm.

"Nights are the worst because you feel like you're outside when you're inside," said Genice Josey, a Far Rockaway resident who has slept under three blankets and wears long johns under her pyjamas in an effort to keep warm. "You shiver yourself to sleep," she added.

In parts of the badly hit borough of Staten Island, it was a similar story.

"When I woke up, I was like: 'It's freezing.' And I thought: 'This can't go on too much longer,'" Sara Zavala said.

Sandy has already been blamed for the deaths of some 113 people in the US, adding to the 69 killed as the hurricane made its way through the Caribbean.

The fear now is that more people may die as a result of hypothermia. The elderly are particularly at risk.

Adding to people's woes is the ongoing scarcity of gas. Long lines at the pumps has becoming a common scene across parts of New York and New Jersey.

Part of the problem has been panic buying by motorists, who have been filling the tank in anticipation of gas running out. New Jersey governor Chris Christie tried to allay the fears of drivers on Sunday, stating that the state did not have "a fuel shortage".

He had earlier ordered a rationing of supply to customers in a bid to head off dwindling supplies.

To help ease the flow, President Barack Obama ordered his administration to release an additional 12m gallons of unleaded fuel and 10m gallons of diesel. Much of that gas was trucked to New Jersey and New York over the weekend and should be delivered by the time the new storm arrives.

Meanwhile, politicians have begun turning up the heat on utility companies over their response to the crisis. A week after the storm struck hundreds of thousands of homes remained subjected to power outages.

On Sunday, Cuomo warned power suppliers that they would be held accountable for any delays that could have been prevented.

"I want them to provide the service that they get paid to perform," he said, adding: "We will be reasonable, but we will hold them accountable."

© Guardian News and Media 2012