BEIJING: Thousands of rescuers were searching for survivors in freezing conditions Wednesday after a devastating earthquake in China's remote Tibet region killed at least 126 people. People trapped or those without shelter are at risk of rapid hypothermia and may only be able to live for five to 10 hours even if uninjured, experts say. Twenty-four hours after the temblor struck, those trapped under rubble would have endured a night in sub-zero temperatures, adding to the pressure on rescuers looking for survivors in an area roughly the size of Cambodia. Temperatures in the high-altitude region dropped as low as minus 18°C (0°F) overnight. Videos published by state broadcaster on Wednesday showed rescue workers pulling injured victims from the rubble of collapsed buildings and carrying them to safety. Footage also showed a man in a dusty, thick winter coat carrying a crying child piggyback as a rescue worker draped a jacket over him. Rescues were also seen setting up makeshift tents and examining the injured inside. At least 188 others injured in the Tuesday morning quake that struck rural, high-altitude Tingri county, about 80 kilometres (50 miles) north of Mount Everest near China's border with Nepal. Local officials said at a press conference on Wednesday afternoon that there had been no increases in the number of people killed or injured since the last update on Tuesday night. More than 3,600 houses had collapsed due to the earthquake and 187 relocation sites have been set up, accommodating 46,500 people, said Hong Li, director of Tibet's Emergency Management Department. The affected region is a "high-altitude, cold plateau area with weak infrastructure such as transportation, communication, and electricity", Hong said. "The climate is cold, with large temperature differences between day and night, and low nighttime temperatures, making it difficult to maintain warmth and protect against the cold," Hong said, adding that search and rescue efforts have transitioned to the resettlement of affected residents and post-disaster reconstruction. The temperature in Tingri will drop to as low as minus 16°C (3.2°F) Thursday morning, according to the China Meteorological Administration.  The county sits at an average altitude of 4,500 metres above sea level. Authorities earlier said more than 12,000 people, including firefighters, soldiers, police officers and professional rescuers, had been deployed, reported. Aid including tents, quilts and cold-weather equipment had been dispatched by central authorities, it added. When tourist Meng Lingkang arrived in the town of Lhatse, 65 kilometres from the epicentre, he saw "the buildings had cracked open". "Some of the older houses collapsed, and a large part of the buildings made from bricks had cracked open, with big fissures," the 23-year-old told . "There were quite a few (rescue vehicles). One after the other they arrived," he added. The China Earthquake Networks Center (CENC) measured the quake's magnitude as 6.8, while the US Geological Survey reported it as 7.1. The area most affected is surrounded by mountainous terrain on the Chinese side of Everest. Tingri, the epicentre, is home to around 62,000 people and much less developed than urban centres like Tibet's capital Lhasa. Many of the fallen houses appeared constructed of traditional materials such as stone, mud bricks and wooden beams. Chinese President Xi Jinping has called for "all-out search and rescue efforts", said.