The coldest weather in 30 years has gripped Beijing, freezing to death two lost hikers and allegedly a homeless man.

After the two climbers from Beijing were reported lost on Saturday afternoon, hundreds of rescuers searched Ling Mountain, where temperatures dropped to minus 30 degrees C.

The two men, aged 25 and 30, where discovered on Sunday at noon, apparently frozen to death, according to the Beijing Firefighting Bureau. Their names were not released.

A volunteer surnamed Mi said that a 40-year-old homeless man named Ni she found shivering in Wangfujing and took to the hospital by ambulance on Saturday died several hours later.

Mi said that Ni was in good condition when he arrived at the hospital. But a few hours later, she said, police called her saying the old man was dead.

"The hospital said that he allegedly died of epilepsy," she said. "Yet we suspect that it's the freezing temperature that caused his death." Mi posted pictures of the man on her microblog.

Mi said that when she got in touch with the Dongcheng district rescue station to inquire, they said that it was pointless to go to the hospital to investigate since the man was already dead. A staff member at the Dongcheng First People's Hospital said she knew nothing about Ni's death.

A staff member who did not give his name from the Dongcheng district rescue station told the Global Times the did not know about the case. "If it's the volunteers who witnessed it, you should ask them instead," he said.

No one from Dongcheng would talk about Ni's death on the record.But officials from the nearby Chaoyang and Xicheng districts said they had never heard of a homeless person freezing to death during winter.

"I knew some who died of their own sickness, but not of the low temperature or starving," said a man surnamed Zhang, the media officer of the Chaoyang district rescue station.

A staff surnamed Ran from the Xicheng district Rescue station said that over 20 people have been rescued since Friday. "Some were found by our staff on the streets, and some came to us on their own," he said. "We sent all of them to the shelters in Mentougou district."

But Ran said the rescue work faces a difficult challenge. "Many homeless people we rescued are beggars who appeared on the streets to beg and refused to be sheltered," he said.

The subzero temperatures caused a jump in heart disease and stroke patients calling for ambulances over the weekend. The number of emergency calls on Friday was 877, up from 818 on Thursday, the Beijing Evening News reported Sunday.

Gao Yang, media officer of the Huairou District Firefighting Bureau, said that they have so far not received any emergency calls concerning mountain climbing, Great Wall climbing, or freezing temperatures in Huairou district.

Despite the cold weather, a staff member of Nanshan Ski Resort said that the freezing temperatures have not affected its daily operation. "We have same amount of visitors here as previous years," she said.

Zhang, the media officer of the Chaoyang district Rescue station, told the Global Times that an intensive collaborative citywide rescue program launched on Friday will continue until Tuesday. "This five-day program is conducted with police and city management officers to find and help homeless people," he said.

"Our searching range has been expanded to streets, underground tunnels and every corner where homeless people might be hiding," he said.

"Any death from freezing weather among homeless people is a huge issue to us," he said, emphasizing that nobody has frozen to death in the district under his rescue coverage.

The Beijing Meteorological Bureau reported Sunday that the temperature on Monday and the day after will warm slightly to minus 11.