At least 15,000 pairs of socks and underwear will be distributed to refugees in Serbia to fight the cold this winter, Oxfam said.
Local suppliers are being identified, a key measure in the British charity's efforts to fill gaps in a massive international aid effort. The clothing will be paid for by money from the public in the UK.
Dobrivoje Stancic, Oxfam's humanitarian affairs co-ordinator in Serbia, said: "We have to be aware that our fund just cannot help everyone and identify every single person in need but what we can do is try to reach out as much as possible."
He said the aid organisation had firm plans until mid-December, when the weather is likely to be much colder.
Mr Stancic added as long as the borders around Serbia were not closed and migrants continued to use the country to reach the west the work would probably continue beyond next month provided resources were available.
"The group is committed and dedicated to continue any kind of support, it is what the people need."
Winter shoes to replace children's tennis shoes are another priority for Oxfam. Although few of the children at one distribution point were barefoot many wore flimsy sports shoes unsuitable for snow.
Aid like cold weather clothing is delivered on a just-in-time basis, Mr Stanic said. When clothes like scarves and gloves were given out too early they tended to be discarded, refugees did not want the extra burden.
At one resting point a man stood in bare feet on plastic bags on the concrete roadside.
Oxfam handed out thousands of pairs of socks and underwear in one day at a service station serving as a muster point about 15 minutes from Serbia's Croatian border.
Afghans mixed with Syrians, Iranians with Libyans.
Arabs sat cross-legged on thin blankets, women with their heads covered cradled children.
Oxfam workers entered buses with tinted windows. The atmosphere was close and quiet, the journey from the other side of Serbia had been long.
A mother and baby lay lengthwise across two seats, the mother with head covered and wrapped in a makeshift cocoon of blankets clutched her child protectively. Some non-Oxfam aid workers wore surgical-style guards across their mouths as they distributed goods.
The coaches had come to a halt until a train was ready to take them into Croatia and another fresh round of paperwork.
A crowd formed around some Oxfam workers on the street outside the bus giving out baby's socks, inquisitive children's hands grabbing in competition for the small pink boxes.
Mr Stancic reached them above some heads to parents with babies. The atmosphere was noisy, there have been incidents before with different nationalities at such close quarters with finite aid and massive numbers of recipients.
The socks were only for very small babies, and as parents with older children arrived, one father laid his hands on his son's shoulders protectively as he crowded closer and was asked to wait for more suitable clothing.
More and more people surrounded the aid distributors in a narrow roadway flanked by lines of buses and the accompanying NGO trucks which have been present at many stages of this traumatic journey.
Amid the privation two children chased each other in circles on rollerblades, gliding backwards playfully and unconcerned.
One man, Manwar Hassan from Aleppo, stood in sandals clutching sports shoes which were too small, obtained in Turkey and still stubbornly clung to, but no socks.
He explained: "They became crumpled and dirty so I threw them away."