UNICEF Ireland is warning that more than 30,000 Syrian refugees are facing a "hostile and unforgiving" winter living in tents in the Jordanian desert.
The aid agency is expanding its operations at the Zaatari camp, which is 15km from the Syrian border.
Staff are currently working to prepare the camp for winter, providing warm clothes, blankets, hot water and winter-proof tents.
UNICEF says many people who have fled the fighting in Syria arrived at the camp ill-equipped for the cold months ahead.
Temperatures can fall below zero, with strong rains, winds and even snow.
UNICEF Ireland Executive Director Peter Power said: "While we were [at Zaatari], nearly 400 new refugees arrived overnight from Syria, so the demand for humanitarian assistance grows daily.
"UNICEF and our partners are scaling up our response to address the most urgent needs of refugees and internally displaced families in the region."
To date, over 1m people have been displaced by violence within Syria and the refugee population at Zaatari is expected to double before the end of the year.
Since UNICEF Ireland launched an appeal for the children of Syria in late August, over €200,000 has been donated.
Anyone wishing to make a donation to UNICEF Ireland's Emergency Appeal for the Children of Syria can visit www.unicef.ie