Vital helicopter flights to help earthquake survivors in northern Pakistan and Kashmir have resumed after a halt caused by weekend storms.
Some survivors have been nursing injuries unattended for nine days
It is estimated that supplies have not yet reached at least 20% of the areas worst affected as key roads remain still blocked by mudslides.
Relief officials warn time is running out to get shelter to the estimated two million homeless before winter arrives.
Deaths in Pakistani-run Kashmir alone may exceed 40,000, local officials say.
Sikander Hayat Khan, the regional prime minister, said he believed that up to 70,000 had also been injured.
Speaking to the BBC's Hindi Service, he called for the border with the Indian sector of Kashmir to be opened up to help the relief effort.
If confirmed, the new death figures would bring the total to 54,000 in all areas affected by the quake.
Quake survivors will die of exposure at night unless proper accommodation is provided, UN aid coordinator Rob Holden said in Muzaffarabad, the capital of Pakistani Kashmir.
Torrential rain and snow threatened people left in the open with little in terms of warm clothing, blankets, food and medical care, he told the BBC.
"It is a race against time and it's a race we're not going to win unless we put a massive amount more effort in getting the goods and services here now," he said.
From first light on Monday, under clear skies, helicopters were flying in and out of Muzaffarabad once again after two days of disruption, the BBC's Mike Wooldridge reports.
Helicopter crews are making hazardous trips into the mountains
Nine days after the quake, the pressure is on from aid officials on the ground to ratchet up the relief operation significantly if lives are to be saved, our correspondent says.
More and more people are being discovered with untreated injuries sustained in the earthquake and, increasingly, their wounds are becoming infected and gangrenous.
"We saw rows of people in a really bad way with suppurating wounds," Sean Keogh, a doctor with British medical aid group Merlin, told Reuters news agency after a three-day trek in the badly-hit Neelum valley.
"There are 1,000 to 2,000 significantly wounded that need surgical treatment. Wounds are pouring pus, patients are going to get septic and die."
The better weather means helicopters can continue evacuating them from areas cut off by road.
A field hospital is being set up in Muzaffarabad but US aid officials say they hope to start flying mobile medical units out to some of the most remote areas soon.