Muzaffarabad, Pakistan ? Freezing temperatures have claimed the lives of at least five Pakistani earthquake survivors, a U.N. health official said Wednesday, as a trickle of villagers descended from mountain settlements in Kashmir to seek shelter on lower ground.

Khalif Bile, of the World Health Organization, said the rate of acute respiratory infections has risen by as much as 19 percent, mostly among children, in the past week. He said five or six deaths have been reported from cold-related diseases since a weekend blast of rain and snow.

U.N. official Zulifquar Wasim said helicopter relief flights resumed Wednesday after being grounded for three days by bad weather. American CH-47 Chinook helicopters and others provided by the U.N. and Pakistan’s army carried flour and aid workers from Muzaffarabad to quake-hit villages.

Bile said 77 teams of five medics were moving through the quake zone to assess the health of survivors. The Oct. 8 quake left some 3.5 million people homeless.