Despite an enormous rescue effort, many people are waiting for help.

ISTANBUL — Almost 10,000 rescuers have fanned out across the 10 Turkish provinces hit by a powerful earthquake and aftershock early Monday, officials said, yet the need remained so vast that as night fell, some places were still waiting for help in the winter cold.

More than 3,450 buildings collapsed in 10 cities of southern and southeast Turkey, according to the Turkish health minister, Fahrettin Koca.

The rescue efforts were hampered by snow and cold. Around 9 p.m. local time in Kahramanmaras, the epicenter of the quake, the temperature stood at around 40 Fahrenheit.

“This is a race against time and hypothermia,” said Mikdat Kadioglu, a professor of meteorology and disaster management at Istanbul Technical University. “People got caught in sleepwear and have been under the rubble for 17 hours,” he said.

The Turkish government sent four helicopters full of rescue teams to Hatay, the country’s southernmost province. Lying to the southwest of the earthquake’s epicenter, it is home to 1.6 million people, bordered by Syria to the east and south, and the Mediterranean to the west. Television coverage showed some of them digging through debris for survivors.

In one city in Hatay, Antakya, a resident who lost his home, Fehim Zeydan, said: “People are trying to save their family members with their bare hands. There is not even a shovel.”

“The municipality office I work in, the governor’s residence, the health directorate building, were destroyed,” Mr. Zeydan added.

The authorities said some rescue teams were still en route to the disaster areas but were hindered by snow and rain. “All the resources of the country deployed to the disaster zone,” said Yunus Sezer, the head of AFAD, Turkey’s emergency agency, in a televised news conference.

According to official figures, in Hayat Province alone, at least 1,200 buildings were destroyed, 520 people were killed, 700 were wounded and an unknown number remained trapped under the rubble.

Mr. Zeydan said he ran to a park during the predawn tremor and waited there until sunrise, then walked around the city to survey the damage, which he called extensive.

In a video he recorded and provided to The New York Times, a wounded man on a blanket lies on the ground, screaming as three other men try to lift him into a wheelchair.

“Why isn’t here one helicopter, or one drone flying over?” Mr. Zeydan said. “We are all alone.”

Two rescue teams were working in Antakya, according to the mayor of Hatay, Lutfu Savas.

“We do our best, but some of our own colleagues are under debris,” he said. “We need help from outside. We need rescue support.”

“The municipality cannot handle this alone,” he added.

Eren Can, a lawyer who lives in Istanbul, said that he had no word about his elderly parents, whose building in Antakya had collapsed, and that he was sure they were buried in the wreckage. But Mr. Can, who got in his car early Monday with his brother to try to drive to Antakya, said rescuers had not yet reached their parents’ neighborhood.

“I am on the road, hoping that they can be rescued,” he said. “I am trying at the same time to push the rescue work to start.”