BERKASOVO, Serbia (AP) — Mohammad Nabi stepped off the bus into the teeth-chattering morning cold, anxiously looking around to see what new hardship awaited his family on their arduous journey toward a new life in Germany.

But to his surprise, an aid worker threw a blanket over his shoulders and directed him down a muddy path leading to the Croatian border that was lined with tents offering free clothes, beverages, food, toilets, phone-charging stations and medical assistance.

"Ah, Europe!" the 30-year-old whispered in relief. "Very thank you, very thank you for helping."

Thousands of asylum-seekers hoping to find sanctuary arrive every day walk down this path, cross into Croatia and climb onto buses heading toward Western Europe.

"My country is very problem, not money, not working," said the former officer who served six years in the Afghan army.

With his wife, two children and all the money he could assemble, he took off from Afghanistan two weeks ago.

But from this point on, transportation, food, medical assistance and beverages will be free as long as the refugees stay in the system that has developed over the past few weeks to help them. The crisis of summer, when asylum-seekers started flooding into Europe, sleeping in cornfields, fainting in the summer heat and playing hide-and-seek with authorities in order to cross into the next country has shifted.

Aid workers say this short stretch between Serbia and Croatia has turned into a welcome center for the river of humanity passing through the Balkans. Volunteers on the Serbian side and government agencies on the Croatian side work day and night to make the autumn cold and rain more bearable for the tired and desperate.

Jelena Grbic from Doctors Without Borders said migrants often arrive in the Balkans unprepared for the cold weather.

"First of all, they are cold," she said. "They are not adequately dressed for these weather conditions. They have no winter clothes, so then they get respiratory diseases. Coughing, infections, fever. Then they are completely exhausted."

More than 180,000 migrants have crossed from Serbia into Croatia since Sept. 15, when Hungary finished a fence on its border with Serbia. Thousands are still coming every day. As winter approaches, more and more are reported ill with respiratory problems.

Abdullah Hallaf from Aleppo, Syria and his family of four at the Serbia-Croatia border on Thursday.

"(The weather) is not a problem for me, but my children are cold. Look at my son here," he said, lifting up shivering 3-year-old Muhammed. "He is all wet. He has no proper clothes or boots for this weather."

Many families struggled with sleepy, exhausted children fed up with the epic trek into Europe and not caring any more for the bananas, sandwiches or water bottles aid workers offered. They walked crying while their parents pulled them by the hand down the muddy path to Croatia.

But at the last tent, just before the border checkpoint, they reach Chris Burton, 22, from Dallas, Texas and Samuel Molina, 27, from Cali, Columbia, volunteers from the Christian aid group "Operation Mobilization."

Samuel jumps in front of the crying children, pulls out his hand pump with a balloon on it, blows it up and quickly twists it into the shape of a dog. As he hands it to the stunned child, a smile replaces the tears.

"A lot of people get off the bus and are afraid. They do not know what their next stop is going to be. We found out that giving a smile and a warm handshake makes all the difference," Burton said.

Molina said buses on the Croatian side were late one day and a huge line of tired, anxious people formed. They started arguing and pushing each other, trying to make sure of their place in line, but he quickly pulled out his guitar and started singing.

Heads turned. Faces changed. Tensions eased.

When the buses finally did arrive, the crowd was dancing, ready for their next phase of their new life.